Timescale 向量 (Postgres)
Timescale Vector 是为 AI 应用而生的
PostgreSQL++向量数据库。
本笔记本展示了如何使用 Postgres 向量数据库 Timescale Vector。您将学习如何使用 TimescaleVector 进行（1）语义搜索，（2）基于时间的向量搜索，（3）自查询，以及（4）如何创建索引来加速查询。
什么是 Timescale Vector？
Timescale Vector 使您能够有效地在 PostgreSQL 中存储和查询数百万个向量嵌入。
- 通过受
DiskANN启发的索引算法，增强pgvector在 1 亿+ 向量上进行更快、更准确的相似性搜索。 - 通过自动基于时间的分割和索引，实现快速的基于时间的向量搜索。
- 为查询向量嵌入和关系数据提供熟悉的 SQL 接口。
Timescale Vector 是云 PostgreSQL，适用于从 POC 到生产的 AI，可以随着您扩展。
- 通过允许您在单个数据库中存储关系元数据、向量嵌入和时间序列数据，简化操作。
- 受益于坚如磐石的 PostgreSQL 基础，具有企业级功能，如流备份和复制、高可用性和行级安全性。
- 通过企业级安全性和合规性实现无忧体验。
如何访问 Timescale Vector
Timescale Vector 可在 Timescale，云 PostgreSQL 平台中使用。（目前没有自托管版本。）
LangChain 用户可获得 Timescale Vector 的 90 天免费试用期。
- 要开始使用，注册 Timescale，创建一个新数据库并按照此笔记本操作！
- 有关更多详细信息和性能基准，请参阅 Timescale Vector 解说博客。
- 有关在 Python 中使用 Timescale Vector 的更多详细信息，请参阅安装说明。
设置
按照以下步骤准备好进行本教程。
# Pip install necessary packages
%pip install --upgrade --quiet timescale-vector
%pip install --upgrade --quiet langchain-openai langchain-community
%pip install --upgrade --quiet tiktoken
在本示例中，我们将使用 OpenAIEmbeddings，所以让我们加载您的 OpenAI API 密钥。
import os
# Run export OPENAI_API_KEY=sk-YOUR_OPENAI_API_KEY...
# Get openAI api key by reading local .env file
from dotenv import find_dotenv, load_dotenv
_ = load_dotenv(find_dotenv())
OPENAI_API_KEY = os.environ["OPENAI_API_KEY"]
# Get the API key and save it as an environment variable
# import os
# import getpass
# os.environ["OPENAI_API_KEY"] = getpass.getpass("OpenAI API Key:")
from typing import Tuple
接下来，我们将导入所需的 Python 库和 LangChain 的库。请注意，我们导入 timescale-vector 库以及 TimescaleVector LangChain 向量存储。
from datetime import datetime, timedelta
from langchain_community.document_loaders import TextLoader
from langchain_community.document_loaders.json_loader import JSONLoader
from langchain_community.vectorstores.timescalevector import TimescaleVector
from langchain_core.documents import Document
from langchain_openai import OpenAIEmbeddings
from langchain_text_splitters import CharacterTextSplitter
API 参考：TextLoader | JSONLoader | TimescaleVector | Document | OpenAIEmbeddings | CharacterTextSplitter
1. 使用欧氏距离的相似性搜索（默认）
首先，我们将看一个在国情咨文演讲中执行相似性搜索查询的示例，以找到与给定查询句子最相似的句子。我们将使用 欧氏距离 作为我们的相似性度量标准。
# Load the text and split it into chunks
loader = TextLoader("../../../extras/modules/state_of_the_union.txt")
documents = loader.load()
text_splitter = CharacterTextSplitter(chunk_size=1000, chunk_overlap=0)
docs = text_splitter.split_documents(documents)
embeddings = OpenAIEmbeddings()
接下来，我们将加载我们的 Timescale 数据库的服务 URL。
如果您还没有这样做，注册 Timescale，并创建一个新数据库。
然后，要连接到您的 PostgreSQL 数据库，您需要您的服务 URI，该 URI 可以在您创建新数据库后下载的备忘单或 .env 文件中找到。
URI 看起来像这样：postgres://tsdbadmin:<password>@<id>.tsdb.cloud.timescale.com:<port>/tsdb?sslmode=require。
# Timescale Vector needs the service url to your cloud database. You can see this as soon as you create the
# service in the cloud UI or in your credentials.sql file
SERVICE_URL = os.environ["TIMESCALE_SERVICE_URL"]
# Specify directly if testing
# SERVICE_URL = "postgres://tsdbadmin:<password>@<id>.tsdb.cloud.timescale.com:<port>/tsdb?sslmode=require"
# # You can get also it from an environment variables. We suggest using a .env file.
# import os
# SERVICE_URL = os.environ.get("TIMESCALE_SERVICE_URL", "")
接下来，我们创建一个 TimescaleVector 向量存储。我们指定一个集合名称，它将是存储我们数据的表的名称。
注意：当创建 TimescaleVector 的新实例时，TimescaleVector 模块将尝试创建一个具有集合名称的表。因此，请确保集合名称是唯一的（即它不存在）。
# The TimescaleVector Module will create a table with the name of the collection.
COLLECTION_NAME = "state_of_the_union_test"
# Create a Timescale Vector instance from the collection of documents
db = TimescaleVector.from_documents(
embedding=embeddings,
documents=docs,
collection_name=COLLECTION_NAME,
service_url=SERVICE_URL,
)
现在我们已经加载了数据，我们可以执行相似性搜索。
query = "What did the president say about Ketanji Brown Jackson"
docs_with_score = db.similarity_search_with_score(query)
for doc, score in docs_with_score:
print("-" * 80)
print("Score: ", score)
print(doc.page_content)
print("-" * 80)
--------------------------------------------------------------------------------
Score: 0.18443380687035138
Tonight. I call on the Senate to: Pass the Freedom to Vote Act. Pass the John Lewis Voting Rights Act. And while you’re at it, pass the Disclose Act so Americans can know who is funding our elections.
Tonight, I’d like to honor someone who has dedicated his life to serve this country: Justice Stephen Breyer—an Army veteran, Constitutional scholar, and retiring Justice of the United States Supreme Court. Justice Breyer, thank you for your service.
One of the most serious constitutional responsibilities a President has is nominating someone to serve on the United States Supreme Court.
And I did that 4 days ago, when I nominated Circuit Court of Appeals Judge Ketanji Brown Jackson. One of our nation’s top legal minds, who will continue Justice Breyer’s legacy of excellence.
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
Score: 0.18452197313308139
Tonight. I call on the Senate to: Pass the Freedom to Vote Act. Pass the John Lewis Voting Rights Act. And while you’re at it, pass the Disclose Act so Americans can know who is funding our elections.
Tonight, I’d like to honor someone who has dedicated his life to serve this country: Justice Stephen Breyer—an Army veteran, Constitutional scholar, and retiring Justice of the United States Supreme Court. Justice Breyer, thank you for your service.
One of the most serious constitutional responsibilities a President has is nominating someone to serve on the United States Supreme Court.
And I did that 4 days ago, when I nominated Circuit Court of Appeals Judge Ketanji Brown Jackson. One of our nation’s top legal minds, who will continue Justice Breyer’s legacy of excellence.
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
Score: 0.21720781018594182
A former top litigator in private practice. A former federal public defender. And from a family of public school educators and police officers. A consensus builder. Since she’s been nominated, she’s received a broad range of support—from the Fraternal Order of Police to former judges appointed by Democrats and Republicans.
And if we are to advance liberty and justice, we need to secure the Border and fix the immigration system.
We can do both. At our border, we’ve installed new technology like cutting-edge scanners to better detect drug smuggling.
We’ve set up joint patrols with Mexico and Guatemala to catch more human traffickers.
We’re putting in place dedicated immigration judges so families fleeing persecution and violence can have their cases heard faster.
We’re securing commitments and supporting partners in South and Central America to host more refugees and secure their own borders.
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
Score: 0.21724902288621384
A former top litigator in private practice. A former federal public defender. And from a family of public school educators and police officers. A consensus builder. Since she’s been nominated, she’s received a broad range of support—from the Fraternal Order of Police to former judges appointed by Democrats and Republicans.
And if we are to advance liberty and justice, we need to secure the Border and fix the immigration system.
We can do both. At our border, we’ve installed new technology like cutting-edge scanners to better detect drug smuggling.
We’ve set up joint patrols with Mexico and Guatemala to catch more human traffickers.
We’re putting in place dedicated immigration judges so families fleeing persecution and violence can have their cases heard faster.
We’re securing commitments and supporting partners in South and Central America to host more refugees and secure their own borders.
--------------------------------------------------------------------------------
将 Timescale Vector 用作检索器
初始化 TimescaleVector 存储后，您可以将其用作检索器。
# Use TimescaleVector as a retriever
retriever = db.as_retriever()
print(retriever)
tags=['TimescaleVector', 'OpenAIEmbeddings'] metadata=None vectorstore=<langchain_community.vectorstores.timescalevector.TimescaleVector object at 0x10fc8d070> search_type='similarity' search_kwargs={}
让我们看一个使用 Timescale Vector 作为检索器的示例，使用 RetrievalQA 链和 stuff 文档链。
在此示例中，我们将提出与上述相同的查询，但这次我们将 Timescale Vector 返回的相关文档传递给 LLM，以用作回答我们问题的上下文。
首先，我们将创建我们的 stuff 链
# Initialize GPT3.5 model
from langchain_openai import ChatOpenAI
llm = ChatOpenAI(temperature=0.1, model="gpt-3.5-turbo-16k")
# Initialize a RetrievalQA class from a stuff chain
from langchain.chains import RetrievalQA
qa_stuff = RetrievalQA.from_chain_type(
llm=llm,
chain_type="stuff",
retriever=retriever,
verbose=True,
)
API 参考：ChatOpenAI | RetrievalQA
query = "What did the president say about Ketanji Brown Jackson?"
response = qa_stuff.run(query)
[1m> Entering new RetrievalQA chain...[0m
[1m> Finished chain.[0m
print(response)
The President said that he nominated Circuit Court of Appeals Judge Ketanji Brown Jackson, who is one of our nation's top legal minds and will continue Justice Breyer's legacy of excellence. He also mentioned that since her nomination, she has received a broad range of support from various groups, including the Fraternal Order of Police and former judges appointed by Democrats and Republicans.
2. 使用基于时间的过滤的相似性搜索
Timescale Vector 的一个关键用例是高效的基于时间的向量搜索。Timescale Vector 通过按时间自动对向量（以及相关元数据）进行分区来实现此目的。这允许您通过与查询向量的相似度和时间来高效查询向量。
基于时间的向量搜索功能对以下应用很有帮助：
- 存储和检索 LLM 响应历史记录（例如，聊天机器人）
- 查找与查询向量相似的最新嵌入（例如，最近的新闻）。
- 将相似性搜索限制在相关的时间范围内（例如，询问有关知识库的基于时间的问题）
为了说明如何使用 Timescale Vector 的基于时间的向量搜索功能，我们将询问有关 TimescaleDB 的 git 日志历史记录的问题。我们将说明如何添加具有基于时间的 uuid 的文档，以及如何运行带有时间范围过滤器的相似性搜索。
从 git 日志 JSON 中提取内容和元数据
首先，让我们将 git 日志数据加载到 PostgreSQL 数据库中名为 timescale_commits 的新集合中。
我们将定义一个辅助函数，根据文档的时间戳为其创建 uuid 和关联的向量嵌入。我们将使用此函数为每个 git 日志条目创建一个 uuid。
重要提示：如果您正在处理文档，并且希望将当前日期和时间与基于时间的搜索的向量相关联，则可以跳过此步骤。默认情况下，当文档被摄入时，会自动生成一个 uuid。
from timescale_vector import client
# Function to take in a date string in the past and return a uuid v1
def create_uuid(date_string: str):
if date_string is None:
return None
time_format = "%a %b %d %H:%M:%S %Y %z"
datetime_obj = datetime.strptime(date_string, time_format)
uuid = client.uuid_from_time(datetime_obj)
return str(uuid)
接下来，我们将定义一个元数据函数，以从 JSON 记录中提取相关的元数据。我们将此函数传递给 JSONLoader。有关更多详细信息，请参阅JSON 文档加载器文档。
# Helper function to split name and email given an author string consisting of Name Lastname <email>
def split_name(input_string: str) -> Tuple[str, str]:
if input_string is None:
return None, None
start = input_string.find("<")
end = input_string.find(">")
name = input_string[:start].strip()
email = input_string[start + 1 : end].strip()
return name, email
# Helper function to transform a date string into a timestamp_tz string
def create_date(input_string: str) -> datetime:
if input_string is None:
return None
# Define a dictionary to map month abbreviations to their numerical equivalents
month_dict = {
"Jan": "01",
"Feb": "02",
"Mar": "03",
"Apr": "04",
"May": "05",
"Jun": "06",
"Jul": "07",
"Aug": "08",
"Sep": "09",
"Oct": "10",
"Nov": "11",
"Dec": "12",
}
# Split the input string into its components
components = input_string.split()
# Extract relevant information
day = components[2]
month = month_dict[components[1]]
year = components[4]
time = components[3]
timezone_offset_minutes = int(components[5]) # Convert the offset to minutes
timezone_hours = timezone_offset_minutes // 60 # Calculate the hours
timezone_minutes = timezone_offset_minutes % 60 # Calculate the remaining minutes
# Create a formatted string for the timestamptz in PostgreSQL format
timestamp_tz_str = (
f"{year}-{month}-{day} {time}+{timezone_hours:02}{timezone_minutes:02}"
)
return timestamp_tz_str
# Metadata extraction function to extract metadata from a JSON record
def extract_metadata(record: dict, metadata: dict) -> dict:
record_name, record_email = split_name(record["author"])
metadata["id"] = create_uuid(record["date"])
metadata["date"] = create_date(record["date"])
metadata["author_name"] = record_name
metadata["author_email"] = record_email
metadata["commit_hash"] = record["commit"]
return metadata
接下来，您需要下载示例数据集并将其放置在与此笔记本相同的目录中。
您可以使用以下命令
# Download the file using curl and save it as commit_history.csv
# Note: Execute this command in your terminal, in the same directory as the notebook
!curl -O https://s3.amazonaws.com/assets.timescale.com/ai/ts_git_log.json
最后，我们可以初始化 JSON 加载器来解析 JSON 记录。为了简单起见，我们还删除了空记录。
# Define path to the JSON file relative to this notebook
# Change this to the path to your JSON file
FILE_PATH = "../../../../../ts_git_log.json"
# Load data from JSON file and extract metadata
loader = JSONLoader(
file_path=FILE_PATH,
jq_schema=".commit_history[]",
text_content=False,
metadata_func=extract_metadata,
)
documents = loader.load()
# Remove documents with None dates
documents = [doc for doc in documents if doc.metadata["date"] is not None]
print(documents[0])
page_content='{"commit": "44e41c12ab25e36c202f58e068ced262eadc8d16", "author": "Lakshmi Narayanan Sreethar<[email protected]>", "date": "Tue Sep 5 21:03:21 2023 +0530", "change summary": "Fix segfault in set_integer_now_func", "change details": "When an invalid function oid is passed to set_integer_now_func, it finds out that the function oid is invalid but before throwing the error, it calls ReleaseSysCache on an invalid tuple causing a segfault. Fixed that by removing the invalid call to ReleaseSysCache. Fixes #6037 "}' metadata={'source': '/Users/avtharsewrathan/sideprojects2023/timescaleai/tsv-langchain/ts_git_log.json', 'seq_num': 1, 'id': '8b407680-4c01-11ee-96a6-b82284ddccc6', 'date': '2023-09-5 21:03:21+0850', 'author_name': 'Lakshmi Narayanan Sreethar', 'author_email': '[email protected]', 'commit_hash': '44e41c12ab25e36c202f58e068ced262eadc8d16'}
将文档和元数据加载到 TimescaleVector 向量存储中
现在我们已经准备好了文档，让我们处理它们，并将它们及其向量嵌入表示形式加载到我们的 TimescaleVector 向量存储中。
由于这是一个演示，我们将仅加载前 500 条记录。在实践中，您可以加载任意数量的记录。
NUM_RECORDS = 500
documents = documents[:NUM_RECORDS]
然后，我们使用 CharacterTextSplitter 将文档拆分为较小的块，以便于嵌入。请注意，此拆分过程会保留每个文档的元数据。
# Split the documents into chunks for embedding
text_splitter = CharacterTextSplitter(
chunk_size=1000,
chunk_overlap=200,
)
docs = text_splitter.split_documents(documents)
接下来，我们将从我们完成预处理的文档集合中创建一个 Timescale Vector 实例。
首先，我们将定义一个集合名称，该名称将是我们在 PostgreSQL 数据库中的表名。
我们还将定义一个时间增量，该时间增量传递给 time_partition_interval 参数，该参数将用作按时间划分数据的间隔。每个分区将包含指定时间长度的数据。为简单起见，我们将使用 7 天，但是您可以选择对您的用例有意义的任何值 - 例如，如果您经常查询最近的向量，则可能需要使用较小的时间增量，例如 1 天，或者如果您查询长达十年的向量，则可能需要使用较大的时间增量，例如 6 个月或 1 年。
最后，我们将创建 TimescaleVector 实例。我们指定 ids 参数为我们在上述预处理步骤中创建的元数据中的 uuid 字段。我们这样做是因为我们希望 uuid 的时间部分反映过去的日期（即，提交的时间）。但是，如果我们希望将当前日期和时间与我们的文档关联，则可以删除 id 参数，并且将使用当前日期和时间自动创建 uuid。
# Define collection name
COLLECTION_NAME = "timescale_commits"
embeddings = OpenAIEmbeddings()
# Create a Timescale Vector instance from the collection of documents
db = TimescaleVector.from_documents(
embedding=embeddings,
ids=[doc.metadata["id"] for doc in docs],
documents=docs,
collection_name=COLLECTION_NAME,
service_url=SERVICE_URL,
time_partition_interval=timedelta(days=7),
)
按时间和相似性查询向量
现在我们已经将文档加载到 TimescaleVector 中，我们可以按时间和相似性查询它们。
TimescaleVector 提供了多种方法，用于通过基于时间的过滤执行相似性搜索来查询向量。
让我们看看下面的每种方法
# Time filter variables
start_dt = datetime(2023, 8, 1, 22, 10, 35) # Start date = 1 August 2023, 22:10:35
end_dt = datetime(2023, 8, 30, 22, 10, 35) # End date = 30 August 2023, 22:10:35
td = timedelta(days=7) # Time delta = 7 days
query = "What's new with TimescaleDB functions?"
方法 1：在提供的开始日期和结束日期内进行过滤。
# Method 1: Query for vectors between start_date and end_date
docs_with_score = db.similarity_search_with_score(
query, start_date=start_dt, end_date=end_dt
)
for doc, score in docs_with_score:
print("-" * 80)
print("Score: ", score)
print("Date: ", doc.metadata["date"])
print(doc.page_content)
print("-" * 80)
--------------------------------------------------------------------------------
Score: 0.17488396167755127
Date: 2023-08-29 18:13:24+0320
{"commit": " e4facda540286b0affba47ccc63959fefe2a7b26", "author": "Sven Klemm<[email protected]>", "date": "Tue Aug 29 18:13:24 2023 +0200", "change summary": "Add compatibility layer for _timescaledb_internal functions", "change details": "With timescaledb 2.12 all the functions present in _timescaledb_internal were moved into the _timescaledb_functions schema to improve schema security. This patch adds a compatibility layer so external callers of these internal functions will not break and allow for more flexibility when migrating. "}
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
Score: 0.18102192878723145
Date: 2023-08-20 22:47:10+0320
{"commit": " 0a66bdb8d36a1879246bd652e4c28500c4b951ab", "author": "Sven Klemm<[email protected]>", "date": "Sun Aug 20 22:47:10 2023 +0200", "change summary": "Move functions to _timescaledb_functions schema", "change details": "To increase schema security we do not want to mix our own internal objects with user objects. Since chunks are created in the _timescaledb_internal schema our internal functions should live in a different dedicated schema. This patch make the necessary adjustments for the following functions: - to_unix_microseconds(timestamptz) - to_timestamp(bigint) - to_timestamp_without_timezone(bigint) - to_date(bigint) - to_interval(bigint) - interval_to_usec(interval) - time_to_internal(anyelement) - subtract_integer_from_now(regclass, bigint) "}
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
Score: 0.18150119891755445
Date: 2023-08-22 12:01:19+0320
{"commit": " cf04496e4b4237440274eb25e4e02472fc4e06fc", "author": "Sven Klemm<[email protected]>", "date": "Tue Aug 22 12:01:19 2023 +0200", "change summary": "Move utility functions to _timescaledb_functions schema", "change details": "To increase schema security we do not want to mix our own internal objects with user objects. Since chunks are created in the _timescaledb_internal schema our internal functions should live in a different dedicated schema. This patch make the necessary adjustments for the following functions: - generate_uuid() - get_git_commit() - get_os_info() - tsl_loaded() "}
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
Score: 0.18422493887617963
Date: 2023-08-9 15:26:03+0500
{"commit": " 44eab9cf9bef34274c88efd37a750eaa74cd8044", "author": "Konstantina Skovola<[email protected]>", "date": "Wed Aug 9 15:26:03 2023 +0300", "change summary": "Release 2.11.2", "change details": "This release contains bug fixes since the 2.11.1 release. We recommend that you upgrade at the next available opportunity. **Features** * #5923 Feature flags for TimescaleDB features **Bugfixes** * #5680 Fix DISTINCT query with JOIN on multiple segmentby columns * #5774 Fixed two bugs in decompression sorted merge code * #5786 Ensure pg_config --cppflags are passed * #5906 Fix quoting owners in sql scripts. * #5912 Fix crash in 1-step integer policy creation **Thanks** * @mrksngl for submitting a PR to fix extension upgrade scripts * @ericdevries for reporting an issue with DISTINCT queries using segmentby columns of compressed hypertable "}
--------------------------------------------------------------------------------
请注意，查询仅返回指定日期范围内的结果。
方法 2：在提供的开始日期和之后的时间增量内进行过滤。
# Method 2: Query for vectors between start_dt and a time delta td later
# Most relevant vectors between 1 August and 7 days later
docs_with_score = db.similarity_search_with_score(
query, start_date=start_dt, time_delta=td
)
for doc, score in docs_with_score:
print("-" * 80)
print("Score: ", score)
print("Date: ", doc.metadata["date"])
print(doc.page_content)
print("-" * 80)
--------------------------------------------------------------------------------
Score: 0.18458807468414307
Date: 2023-08-3 14:30:23+0500
{"commit": " 7aeed663b9c0f337b530fd6cad47704a51a9b2ec", "author": "Dmitry Simonenko<[email protected]>", "date": "Thu Aug 3 14:30:23 2023 +0300", "change summary": "Feature flags for TimescaleDB features", "change details": "This PR adds several GUCs which allow to enable/disable major timescaledb features: - enable_hypertable_create - enable_hypertable_compression - enable_cagg_create - enable_policy_create "}
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
Score: 0.20492422580718994
Date: 2023-08-7 18:31:40+0320
{"commit": " 07762ea4cedefc88497f0d1f8712d1515cdc5b6e", "author": "Sven Klemm<[email protected]>", "date": "Mon Aug 7 18:31:40 2023 +0200", "change summary": "Test timescaledb debian 12 packages in CI", "change details": ""}
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
Score: 0.21106326580047607
Date: 2023-08-3 14:36:39+0500
{"commit": " 2863daf3df83c63ee36c0cf7b66c522da5b4e127", "author": "Dmitry Simonenko<[email protected]>", "date": "Thu Aug 3 14:36:39 2023 +0300", "change summary": "Support CREATE INDEX ONLY ON main table", "change details": "This PR adds support for CREATE INDEX ONLY ON clause which allows to create index only on the main table excluding chunks. Fix #5908 "}
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
Score: 0.21698051691055298
Date: 2023-08-2 20:24:14+0140
{"commit": " 3af0d282ea71d9a8f27159a6171e9516e62ec9cb", "author": "Lakshmi Narayanan Sreethar<[email protected]>", "date": "Wed Aug 2 20:24:14 2023 +0100", "change summary": "PG16: ExecInsertIndexTuples requires additional parameter", "change details": "PG16 adds a new boolean parameter to the ExecInsertIndexTuples function to denote if the index is a BRIN index, which is then used to determine if the index update can be skipped. The fix also removes the INDEX_ATTR_BITMAP_ALL enum value. Adapt these changes by updating the compat function to accomodate the new parameter added to the ExecInsertIndexTuples function and using an alternative for the removed INDEX_ATTR_BITMAP_ALL enum value. postgres/postgres@19d8e23 "}
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再次注意，我们如何在指定的时间过滤器内获得结果，这与之前的查询不同。
方法 3：在提供的结束日期和之前的时间增量内进行过滤。
# Method 3: Query for vectors between end_dt and a time delta td earlier
# Most relevant vectors between 30 August and 7 days earlier
docs_with_score = db.similarity_search_with_score(query, end_date=end_dt, time_delta=td)
for doc, score in docs_with_score:
print("-" * 80)
print("Score: ", score)
print("Date: ", doc.metadata["date"])
print(doc.page_content)
print("-" * 80)
--------------------------------------------------------------------------------
Score: 0.17488396167755127
Date: 2023-08-29 18:13:24+0320
{"commit": " e4facda540286b0affba47ccc63959fefe2a7b26", "author": "Sven Klemm<[email protected]>", "date": "Tue Aug 29 18:13:24 2023 +0200", "change summary": "Add compatibility layer for _timescaledb_internal functions", "change details": "With timescaledb 2.12 all the functions present in _timescaledb_internal were moved into the _timescaledb_functions schema to improve schema security. This patch adds a compatibility layer so external callers of these internal functions will not break and allow for more flexibility when migrating. "}
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
Score: 0.18496227264404297
Date: 2023-08-29 10:49:47+0320
{"commit": " a9751ccd5eb030026d7b975d22753f5964972389", "author": "Sven Klemm<[email protected]>", "date": "Tue Aug 29 10:49:47 2023 +0200", "change summary": "Move partitioning functions to _timescaledb_functions schema", "change details": "To increase schema security we do not want to mix our own internal objects with user objects. Since chunks are created in the _timescaledb_internal schema our internal functions should live in a different dedicated schema. This patch make the necessary adjustments for the following functions: - get_partition_for_key(val anyelement) - get_partition_hash(val anyelement) "}
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
Score: 0.1871250867843628
Date: 2023-08-28 23:26:23+0320
{"commit": " b2a91494a11d8b82849b6f11f9ea6dc26ef8a8cb", "author": "Sven Klemm<[email protected]>", "date": "Mon Aug 28 23:26:23 2023 +0200", "change summary": "Move ddl_internal functions to _timescaledb_functions schema", "change details": "To increase schema security we do not want to mix our own internal objects with user objects. Since chunks are created in the _timescaledb_internal schema our internal functions should live in a different dedicated schema. This patch make the necessary adjustments for the following functions: - chunk_constraint_add_table_constraint(_timescaledb_catalog.chunk_constraint) - chunk_drop_replica(regclass,name) - chunk_index_clone(oid) - chunk_index_replace(oid,oid) - create_chunk_replica_table(regclass,name) - drop_stale_chunks(name,integer[]) - health() - hypertable_constraint_add_table_fk_constraint(name,name,name,integer) - process_ddl_event() - wait_subscription_sync(name,name,integer,numeric) "}
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
Score: 0.18867712088363497
Date: 2023-08-27 13:20:04+0320
{"commit": " e02b1f348eb4c48def00b7d5227238b4d9d41a4a", "author": "Sven Klemm<[email protected]>", "date": "Sun Aug 27 13:20:04 2023 +0200", "change summary": "Simplify schema move update script", "change details": "Use dynamic sql to create the ALTER FUNCTION statements for those functions that may not exist in previous versions. "}
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方法 4：我们还可以通过仅在查询中指定开始日期来过滤给定日期之后的所有向量。
方法 5：类似地，我们还可以通过仅指定查询中的结束日期来过滤给定日期之前的所有向量。
# Method 4: Query all vectors after start_date
docs_with_score = db.similarity_search_with_score(query, start_date=start_dt)
for doc, score in docs_with_score:
print("-" * 80)
print("Score: ", score)
print("Date: ", doc.metadata["date"])
print(doc.page_content)
print("-" * 80)
--------------------------------------------------------------------------------
Score: 0.17488396167755127
Date: 2023-08-29 18:13:24+0320
{"commit": " e4facda540286b0affba47ccc63959fefe2a7b26", "author": "Sven Klemm<[email protected]>", "date": "Tue Aug 29 18:13:24 2023 +0200", "change summary": "Add compatibility layer for _timescaledb_internal functions", "change details": "With timescaledb 2.12 all the functions present in _timescaledb_internal were moved into the _timescaledb_functions schema to improve schema security. This patch adds a compatibility layer so external callers of these internal functions will not break and allow for more flexibility when migrating. "}
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
Score: 0.18102192878723145
Date: 2023-08-20 22:47:10+0320
{"commit": " 0a66bdb8d36a1879246bd652e4c28500c4b951ab", "author": "Sven Klemm<[email protected]>", "date": "Sun Aug 20 22:47:10 2023 +0200", "change summary": "Move functions to _timescaledb_functions schema", "change details": "To increase schema security we do not want to mix our own internal objects with user objects. Since chunks are created in the _timescaledb_internal schema our internal functions should live in a different dedicated schema. This patch make the necessary adjustments for the following functions: - to_unix_microseconds(timestamptz) - to_timestamp(bigint) - to_timestamp_without_timezone(bigint) - to_date(bigint) - to_interval(bigint) - interval_to_usec(interval) - time_to_internal(anyelement) - subtract_integer_from_now(regclass, bigint) "}
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
Score: 0.18150119891755445
Date: 2023-08-22 12:01:19+0320
{"commit": " cf04496e4b4237440274eb25e4e02472fc4e06fc", "author": "Sven Klemm<[email protected]>", "date": "Tue Aug 22 12:01:19 2023 +0200", "change summary": "Move utility functions to _timescaledb_functions schema", "change details": "To increase schema security we do not want to mix our own internal objects with user objects. Since chunks are created in the _timescaledb_internal schema our internal functions should live in a different dedicated schema. This patch make the necessary adjustments for the following functions: - generate_uuid() - get_git_commit() - get_os_info() - tsl_loaded() "}
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
Score: 0.18422493887617963
Date: 2023-08-9 15:26:03+0500
{"commit": " 44eab9cf9bef34274c88efd37a750eaa74cd8044", "author": "Konstantina Skovola<[email protected]>", "date": "Wed Aug 9 15:26:03 2023 +0300", "change summary": "Release 2.11.2", "change details": "This release contains bug fixes since the 2.11.1 release. We recommend that you upgrade at the next available opportunity. **Features** * #5923 Feature flags for TimescaleDB features **Bugfixes** * #5680 Fix DISTINCT query with JOIN on multiple segmentby columns * #5774 Fixed two bugs in decompression sorted merge code * #5786 Ensure pg_config --cppflags are passed * #5906 Fix quoting owners in sql scripts. * #5912 Fix crash in 1-step integer policy creation **Thanks** * @mrksngl for submitting a PR to fix extension upgrade scripts * @ericdevries for reporting an issue with DISTINCT queries using segmentby columns of compressed hypertable "}
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# Method 5: Query all vectors before end_date
docs_with_score = db.similarity_search_with_score(query, end_date=end_dt)
for doc, score in docs_with_score:
print("-" * 80)
print("Score: ", score)
print("Date: ", doc.metadata["date"])
print(doc.page_content)
print("-" * 80)
--------------------------------------------------------------------------------
Score: 0.16723191738128662
Date: 2023-04-11 22:01:14+0320
{"commit": " 0595ff0888f2ffb8d313acb0bda9642578a9ade3", "author": "Sven Klemm<[email protected]>", "date": "Tue Apr 11 22:01:14 2023 +0200", "change summary": "Move type support functions into _timescaledb_functions schema", "change details": ""}
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
Score: 0.1706540584564209
Date: 2023-04-6 13:00:00+0320
{"commit": " 04f43335dea11e9c467ee558ad8edfc00c1a45ed", "author": "Sven Klemm<[email protected]>", "date": "Thu Apr 6 13:00:00 2023 +0200", "change summary": "Move aggregate support function into _timescaledb_functions", "change details": "This patch moves the support functions for histogram, first and last into the _timescaledb_functions schema. Since we alter the schema of the existing functions in upgrade scripts and do not change the aggregates this should work completely transparently for any user objects using those aggregates. "}
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
Score: 0.17462033033370972
Date: 2023-03-31 08:22:57+0320
{"commit": " feef9206facc5c5f506661de4a81d96ef059b095", "author": "Sven Klemm<[email protected]>", "date": "Fri Mar 31 08:22:57 2023 +0200", "change summary": "Add _timescaledb_functions schema", "change details": "Currently internal user objects like chunks and our functions live in the same schema making locking down that schema hard. This patch adds a new schema _timescaledb_functions that is meant to be the schema used for timescaledb internal functions to allow separation of code and chunks or other user objects. "}
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
Score: 0.17488396167755127
Date: 2023-08-29 18:13:24+0320
{"commit": " e4facda540286b0affba47ccc63959fefe2a7b26", "author": "Sven Klemm<[email protected]>", "date": "Tue Aug 29 18:13:24 2023 +0200", "change summary": "Add compatibility layer for _timescaledb_internal functions", "change details": "With timescaledb 2.12 all the functions present in _timescaledb_internal were moved into the _timescaledb_functions schema to improve schema security. This patch adds a compatibility layer so external callers of these internal functions will not break and allow for more flexibility when migrating. "}
--------------------------------------------------------------------------------
主要的要点是，在上面的每个结果中，仅返回指定时间范围内的向量。这些查询非常有效，因为它们只需要搜索相关的分区。
我们还可以将此功能用于问答，我们希望在指定的时间范围内找到最相关的向量，以用作回答问题的上下文。让我们看看下面的示例，将 Timescale Vector 用作检索器
# Set timescale vector as a retriever and specify start and end dates via kwargs
retriever = db.as_retriever(search_kwargs={"start_date": start_dt, "end_date": end_dt})
from langchain_openai import ChatOpenAI
llm = ChatOpenAI(temperature=0.1, model="gpt-3.5-turbo-16k")
from langchain.chains import RetrievalQA
qa_stuff = RetrievalQA.from_chain_type(
llm=llm,
chain_type="stuff",
retriever=retriever,
verbose=True,
)
query = (
"What's new with the timescaledb functions? Tell me when these changes were made."
)
response = qa_stuff.run(query)
print(response)
API 参考：ChatOpenAI | RetrievalQA
[1m> Entering new RetrievalQA chain...[0m
[1m> Finished chain.[0m
The following changes were made to the timescaledb functions:
1. "Add compatibility layer for _timescaledb_internal functions" - This change was made on Tue Aug 29 18:13:24 2023 +0200.
2. "Move functions to _timescaledb_functions schema" - This change was made on Sun Aug 20 22:47:10 2023 +0200.
3. "Move utility functions to _timescaledb_functions schema" - This change was made on Tue Aug 22 12:01:19 2023 +0200.
4. "Move partitioning functions to _timescaledb_functions schema" - This change was made on Tue Aug 29 10:49:47 2023 +0200.
请注意，LLM 用来组合答案的上下文来自仅在指定日期范围内检索到的文档。
这显示了如何使用 Timescale Vector 通过检索与查询相关的时间范围内的文档来增强检索增强生成。
3. 使用 ANN 搜索索引来加速查询
您可以通过在嵌入列上创建索引来加快相似性查询。仅在您摄入了大部分数据后才应执行此操作。
Timescale Vector 支持以下索引
- timescale_vector 索引 (tsv)：受磁盘 ANN 启发的图索引，用于快速相似性搜索（默认）。
- pgvector 的 HNSW 索引：分层可导航小世界图索引，用于快速相似性搜索。
- pgvector 的 IVFFLAT 索引：倒排文件索引，用于快速相似性搜索。
重要提示：在 PostgreSQL 中，每个表在特定列上只能有一个索引。因此，如果您想测试不同索引类型的性能，可以通过 (1) 创建多个具有不同索引的表，(2) 在同一表中创建多个向量列并在每列上创建不同的索引，或者 (3) 删除并在同一列上重新创建索引并比较结果。
# Initialize an existing TimescaleVector store
COLLECTION_NAME = "timescale_commits"
embeddings = OpenAIEmbeddings()
db = TimescaleVector(
collection_name=COLLECTION_NAME,
service_url=SERVICE_URL,
embedding_function=embeddings,
)
使用不带额外参数的 create_index() 函数将默认创建一个 timescale_vector_index，并使用默认参数。
# create an index
# by default this will create a Timescale Vector (DiskANN) index
db.create_index()
你也可以为索引指定参数。有关不同参数及其对性能的影响的完整讨论，请参阅 Timescale Vector 文档。
注意：你不需要指定参数，因为我们设置了智能默认值。但是，如果你想为你的特定数据集尝试获得更高的性能，你可以随时指定自己的参数。
# drop the old index
db.drop_index()
# create an index
# Note: You don't need to specify m and ef_construction parameters as we set smart defaults.
db.create_index(index_type="tsv", max_alpha=1.0, num_neighbors=50)
Timescale Vector 还支持 HNSW ANN 索引算法以及 ivfflat ANN 索引算法。只需在 index_type 参数中指定要创建的索引类型，并可选择为该索引指定参数。
# drop the old index
db.drop_index()
# Create an HNSW index
# Note: You don't need to specify m and ef_construction parameters as we set smart defaults.
db.create_index(index_type="hnsw", m=16, ef_construction=64)
# drop the old index
db.drop_index()
# Create an IVFFLAT index
# Note: You don't need to specify num_lists and num_records parameters as we set smart defaults.
db.create_index(index_type="ivfflat", num_lists=20, num_records=1000)
通常，我们建议使用默认的 timescale vector 索引或 HNSW 索引。
# drop the old index
db.drop_index()
# Create a new timescale vector index
db.create_index()
4. 使用 Timescale Vector 的自查询检索器
Timescale Vector 还支持自查询检索器功能，使其能够查询自身。给定一个包含查询语句和过滤器（单个或复合）的自然语言查询，检索器使用查询构建 LLM 链来编写 SQL 查询，然后将其应用于 Timescale Vector 向量存储中的底层 PostgreSQL 数据库。
有关自查询的更多信息，请参阅文档。
为了说明 Timescale Vector 的自查询功能，我们将使用第 3 部分中的相同 gitlog 数据集。
COLLECTION_NAME = "timescale_commits"
vectorstore = TimescaleVector(
embedding_function=OpenAIEmbeddings(),
collection_name=COLLECTION_NAME,
service_url=SERVICE_URL,
)
接下来，我们将创建自查询检索器。为此，我们需要预先提供一些关于文档支持的元数据字段的信息以及文档内容的简短描述。
from langchain.chains.query_constructor.base import AttributeInfo
from langchain.retrievers.self_query.base import SelfQueryRetriever
from langchain_openai import OpenAI
# Give LLM info about the metadata fields
metadata_field_info = [
AttributeInfo(
name="id",
description="A UUID v1 generated from the date of the commit",
type="uuid",
),
AttributeInfo(
name="date",
description="The date of the commit in timestamptz format",
type="timestamptz",
),
AttributeInfo(
name="author_name",
description="The name of the author of the commit",
type="string",
),
AttributeInfo(
name="author_email",
description="The email address of the author of the commit",
type="string",
),
]
document_content_description = "The git log commit summary containing the commit hash, author, date of commit, change summary and change details"
# Instantiate the self-query retriever from an LLM
llm = OpenAI(temperature=0)
retriever = SelfQueryRetriever.from_llm(
llm,
vectorstore,
document_content_description,
metadata_field_info,
enable_limit=True,
verbose=True,
)
现在，让我们在 gitlog 数据集上测试一下自查询检索器。
运行以下查询，并注意如何在自然语言中指定查询、带有过滤器的查询以及带有复合过滤器（带有 AND、OR 的过滤器）的查询，自查询检索器会将该查询转换为 SQL，并在 Timescale Vector PostgreSQL 向量存储上执行搜索。
这说明了自查询检索器的强大功能。你可以使用它对向量存储执行复杂的搜索，而你或你的用户无需直接编写任何 SQL！
# This example specifies a relevant query
retriever.invoke("What are improvements made to continuous aggregates?")
/Users/avtharsewrathan/sideprojects2023/timescaleai/tsv-langchain/langchain/libs/langchain/langchain/chains/llm.py:275: UserWarning: The predict_and_parse method is deprecated, instead pass an output parser directly to LLMChain.
warnings.warn(
``````output
query='improvements to continuous aggregates' filter=None limit=None
[Document(page_content='{"commit": " 35c91204987ccb0161d745af1a39b7eb91bc65a5", "author": "Fabr\\u00edzio de Royes Mello<[email protected]>", "date": "Thu Nov 24 13:19:36 2022 -0300", "change summary": "Add Hierarchical Continuous Aggregates validations", "change details": "Commit 3749953e introduce Hierarchical Continuous Aggregates (aka Continuous Aggregate on top of another Continuous Aggregate) but it lacks of some basic validations. Validations added during the creation of a Hierarchical Continuous Aggregate: * Forbid create a continuous aggregate with fixed-width bucket on top of a continuous aggregate with variable-width bucket. * Forbid incompatible bucket widths: - should not be equal; - bucket width of the new continuous aggregate should be greater than the source continuous aggregate; - bucket width of the new continuous aggregate should be multiple of the source continuous aggregate. "}', metadata={'id': 'c98d1c00-6c13-11ed-9bbe-23925ce74d13', 'date': '2022-11-24 13:19:36+-500', 'source': '/Users/avtharsewrathan/sideprojects2023/timescaleai/tsv-langchain/langchain/docs/docs/modules/ts_git_log.json', 'seq_num': 446, 'author_name': 'Fabrízio de Royes Mello', 'commit_hash': ' 35c91204987ccb0161d745af1a39b7eb91bc65a5', 'author_email': '[email protected]'}),
Document(page_content='{"commit": " 3749953e9704e45df8f621607989ada0714ce28d", "author": "Fabr\\u00edzio de Royes Mello<[email protected]>", "date": "Wed Oct 5 18:45:40 2022 -0300", "change summary": "Hierarchical Continuous Aggregates", "change details": "Enable users create Hierarchical Continuous Aggregates (aka Continuous Aggregates on top of another Continuous Aggregates). With this PR users can create levels of aggregation granularity in Continuous Aggregates making the refresh process even faster. A problem with this feature can be in upper levels we can end up with the \\"average of averages\\". But to get the \\"real average\\" we can rely on \\"stats_aggs\\" TimescaleDB Toolkit function that calculate and store the partials that can be finalized with other toolkit functions like \\"average\\" and \\"sum\\". Closes #1400 "}', metadata={'id': '0df31a00-44f7-11ed-9794-ebcc1227340f', 'date': '2022-10-5 18:45:40+-500', 'source': '/Users/avtharsewrathan/sideprojects2023/timescaleai/tsv-langchain/langchain/docs/docs/modules/ts_git_log.json', 'seq_num': 470, 'author_name': 'Fabrízio de Royes Mello', 'commit_hash': ' 3749953e9704e45df8f621607989ada0714ce28d', 'author_email': '[email protected]'}),
Document(page_content='{"commit": " a6ff7ba6cc15b280a275e5acd315741ec9c86acc", "author": "Mats Kindahl<[email protected]>", "date": "Tue Feb 28 12:04:17 2023 +0100", "change summary": "Rename columns in old-style continuous aggregates", "change details": "For continuous aggregates with the old-style partial aggregates renaming columns that are not in the group-by clause will generate an error when upgrading to a later version. The reason is that it is implicitly assumed that the name of the column is the same as for the direct view. This holds true for new-style continous aggregates, but is not always true for old-style continuous aggregates. In particular, columns that are not part of the `GROUP BY` clause can have an internally generated name. This commit fixes that by extracting the name of the column from the partial view and use that when renaming the partial view column and the materialized table column. "}', metadata={'id': 'a49ace80-b757-11ed-8138-2390fd44ffd9', 'date': '2023-02-28 12:04:17+0140', 'source': '/Users/avtharsewrathan/sideprojects2023/timescaleai/tsv-langchain/langchain/docs/docs/modules/ts_git_log.json', 'seq_num': 294, 'author_name': 'Mats Kindahl', 'commit_hash': ' a6ff7ba6cc15b280a275e5acd315741ec9c86acc', 'author_email': '[email protected]'}),
Document(page_content='{"commit": " 5bba74a2ec083728f8e93e09d03d102568fd72b5", "author": "Fabr\\u00edzio de Royes Mello<[email protected]>", "date": "Mon Aug 7 19:49:47 2023 -0300", "change summary": "Relax strong table lock when refreshing a CAGG", "change details": "When refreshing a Continuous Aggregate we take a table lock on _timescaledb_catalog.continuous_aggs_invalidation_threshold when processing the invalidation logs (the first transaction of the refresh Continuous Aggregate procedure). It means that even two different Continuous Aggregates over two different hypertables will wait each other in the first phase of the refreshing procedure. Also it lead to problems when a pg_dump is running because it take an AccessShareLock on tables so Continuous Aggregate refresh execution will wait until the pg_dump finish. Improved it by relaxing the strong table-level lock to a row-level lock so now the Continuous Aggregate refresh procedure can be executed in multiple sessions with less locks. Fix #3554 "}', metadata={'id': 'b5583780-3574-11ee-a5ba-2e305874a58f', 'date': '2023-08-7 19:49:47+-500', 'source': '/Users/avtharsewrathan/sideprojects2023/timescaleai/tsv-langchain/langchain/docs/docs/modules/ts_git_log.json', 'seq_num': 27, 'author_name': 'Fabrízio de Royes Mello', 'commit_hash': ' 5bba74a2ec083728f8e93e09d03d102568fd72b5', 'author_email': '[email protected]'})]
# This example specifies a filter
retriever.invoke("What commits did Sven Klemm add?")
query=' ' filter=Comparison(comparator=<Comparator.EQ: 'eq'>, attribute='author_name', value='Sven Klemm') limit=None
[Document(page_content='{"commit": " e2e7ae304521b74ac6b3f157a207da047d44ab06", "author": "Sven Klemm<[email protected]>", "date": "Fri Mar 3 11:22:06 2023 +0100", "change summary": "Don\'t run sanitizer test on individual PRs", "change details": "Sanitizer tests take a long time to run so we don\'t want to run them on individual PRs but instead run them nightly and on commits to master. "}', metadata={'id': '3f401b00-b9ad-11ed-b5ea-a3fd40b9ac16', 'date': '2023-03-3 11:22:06+0140', 'source': '/Users/avtharsewrathan/sideprojects2023/timescaleai/tsv-langchain/langchain/docs/docs/modules/ts_git_log.json', 'seq_num': 295, 'author_name': 'Sven Klemm', 'commit_hash': ' e2e7ae304521b74ac6b3f157a207da047d44ab06', 'author_email': '[email protected]'}),
Document(page_content='{"commit": " d8f19e57a04d17593df5f2c694eae8775faddbc7", "author": "Sven Klemm<[email protected]>", "date": "Wed Feb 1 08:34:20 2023 +0100", "change summary": "Bump version of setup-wsl github action", "change details": "The currently used version pulls in Node.js 12 which is deprecated on github. https://github.blog/changelog/2022-09-22-github-actions-all-actions-will-begin-running-on-node16-instead-of-node12/ "}', metadata={'id': 'd70de600-a202-11ed-85d6-30b6df240f49', 'date': '2023-02-1 08:34:20+0140', 'source': '/Users/avtharsewrathan/sideprojects2023/timescaleai/tsv-langchain/langchain/docs/docs/modules/ts_git_log.json', 'seq_num': 350, 'author_name': 'Sven Klemm', 'commit_hash': ' d8f19e57a04d17593df5f2c694eae8775faddbc7', 'author_email': '[email protected]'}),
Document(page_content='{"commit": " 83b13cf6f73a74656dde9cc6ec6cf76740cddd3c", "author": "Sven Klemm<[email protected]>", "date": "Fri Nov 25 08:27:45 2022 +0100", "change summary": "Use packaged postgres for sqlsmith and coverity CI", "change details": "The sqlsmith and coverity workflows used the cache postgres build but could not produce a build by themselves and therefore relied on other workflows to produce the cached binaries. This patch changes those workflows to use normal postgres packages instead of custom built postgres to remove that dependency. "}', metadata={'id': 'a786ae80-6c92-11ed-bd6c-a57bd3348b97', 'date': '2022-11-25 08:27:45+0140', 'source': '/Users/avtharsewrathan/sideprojects2023/timescaleai/tsv-langchain/langchain/docs/docs/modules/ts_git_log.json', 'seq_num': 447, 'author_name': 'Sven Klemm', 'commit_hash': ' 83b13cf6f73a74656dde9cc6ec6cf76740cddd3c', 'author_email': '[email protected]'}),
Document(page_content='{"commit": " b1314e63f2ff6151ab5becfb105afa3682286a4d", "author": "Sven Klemm<[email protected]>", "date": "Thu Dec 22 12:03:35 2022 +0100", "change summary": "Fix RPM package test for PG15 on centos 7", "change details": "Installing PG15 on Centos 7 requires the EPEL repository to satisfy the dependencies. "}', metadata={'id': '477b1d80-81e8-11ed-9c8c-9b5abbd67c98', 'date': '2022-12-22 12:03:35+0140', 'source': '/Users/avtharsewrathan/sideprojects2023/timescaleai/tsv-langchain/langchain/docs/docs/modules/ts_git_log.json', 'seq_num': 408, 'author_name': 'Sven Klemm', 'commit_hash': ' b1314e63f2ff6151ab5becfb105afa3682286a4d', 'author_email': '[email protected]'})]
# This example specifies a query and filter
retriever.invoke("What commits about timescaledb_functions did Sven Klemm add?")
query='timescaledb_functions' filter=Comparison(comparator=<Comparator.EQ: 'eq'>, attribute='author_name', value='Sven Klemm') limit=None
[Document(page_content='{"commit": " 04f43335dea11e9c467ee558ad8edfc00c1a45ed", "author": "Sven Klemm<[email protected]>", "date": "Thu Apr 6 13:00:00 2023 +0200", "change summary": "Move aggregate support function into _timescaledb_functions", "change details": "This patch moves the support functions for histogram, first and last into the _timescaledb_functions schema. Since we alter the schema of the existing functions in upgrade scripts and do not change the aggregates this should work completely transparently for any user objects using those aggregates. "}', metadata={'id': '2cb47800-d46a-11ed-8f0e-2b624245c561', 'date': '2023-04-6 13:00:00+0320', 'source': '/Users/avtharsewrathan/sideprojects2023/timescaleai/tsv-langchain/langchain/docs/docs/modules/ts_git_log.json', 'seq_num': 233, 'author_name': 'Sven Klemm', 'commit_hash': ' 04f43335dea11e9c467ee558ad8edfc00c1a45ed', 'author_email': '[email protected]'}),
Document(page_content='{"commit": " feef9206facc5c5f506661de4a81d96ef059b095", "author": "Sven Klemm<[email protected]>", "date": "Fri Mar 31 08:22:57 2023 +0200", "change summary": "Add _timescaledb_functions schema", "change details": "Currently internal user objects like chunks and our functions live in the same schema making locking down that schema hard. This patch adds a new schema _timescaledb_functions that is meant to be the schema used for timescaledb internal functions to allow separation of code and chunks or other user objects. "}', metadata={'id': '7a257680-cf8c-11ed-848c-a515e8687479', 'date': '2023-03-31 08:22:57+0320', 'source': '/Users/avtharsewrathan/sideprojects2023/timescaleai/tsv-langchain/langchain/docs/docs/modules/ts_git_log.json', 'seq_num': 239, 'author_name': 'Sven Klemm', 'commit_hash': ' feef9206facc5c5f506661de4a81d96ef059b095', 'author_email': '[email protected]'}),
Document(page_content='{"commit": " 0a66bdb8d36a1879246bd652e4c28500c4b951ab", "author": "Sven Klemm<[email protected]>", "date": "Sun Aug 20 22:47:10 2023 +0200", "change summary": "Move functions to _timescaledb_functions schema", "change details": "To increase schema security we do not want to mix our own internal objects with user objects. Since chunks are created in the _timescaledb_internal schema our internal functions should live in a different dedicated schema. This patch make the necessary adjustments for the following functions: - to_unix_microseconds(timestamptz) - to_timestamp(bigint) - to_timestamp_without_timezone(bigint) - to_date(bigint) - to_interval(bigint) - interval_to_usec(interval) - time_to_internal(anyelement) - subtract_integer_from_now(regclass, bigint) "}', metadata={'id': 'bb99db00-3f9a-11ee-a8dc-0b9c1a5a37c4', 'date': '2023-08-20 22:47:10+0320', 'source': '/Users/avtharsewrathan/sideprojects2023/timescaleai/tsv-langchain/langchain/docs/docs/modules/ts_git_log.json', 'seq_num': 41, 'author_name': 'Sven Klemm', 'commit_hash': ' 0a66bdb8d36a1879246bd652e4c28500c4b951ab', 'author_email': '[email protected]'}),
Document(page_content='{"commit": " 56ea8b4de93cefc38e002202d8ac96947dcbaa77", "author": "Sven Klemm<[email protected]>", "date": "Thu Apr 13 13:16:14 2023 +0200", "change summary": "Move trigger functions to _timescaledb_functions schema", "change details": "To increase schema security we do not want to mix our own internal objects with user objects. Since chunks are created in the _timescaledb_internal schema our internal functions should live in a different dedicated schema. This patch make the necessary adjustments for our trigger functions. "}', metadata={'id': '9a255300-d9ec-11ed-988f-7086c8ca463a', 'date': '2023-04-13 13:16:14+0320', 'source': '/Users/avtharsewrathan/sideprojects2023/timescaleai/tsv-langchain/langchain/docs/docs/modules/ts_git_log.json', 'seq_num': 44, 'author_name': 'Sven Klemm', 'commit_hash': ' 56ea8b4de93cefc38e002202d8ac96947dcbaa77', 'author_email': '[email protected]'})]
# This example specifies a time-based filter
retriever.invoke("What commits were added in July 2023?")
query=' ' filter=Operation(operator=<Operator.AND: 'and'>, arguments=[Comparison(comparator=<Comparator.GTE: 'gte'>, attribute='date', value='2023-07-01T00:00:00Z'), Comparison(comparator=<Comparator.LTE: 'lte'>, attribute='date', value='2023-07-31T23:59:59Z')]) limit=None
[Document(page_content='{"commit": " 5cf354e2469ee7e43248bed382a4b49fc7ccfecd", "author": "Markus Engel<[email protected]>", "date": "Mon Jul 31 11:28:25 2023 +0200", "change summary": "Fix quoting owners in sql scripts.", "change details": "When referring to a role from a string type, it must be properly quoted using pg_catalog.quote_ident before it can be casted to regrole. Fixed this, especially in update scripts. "}', metadata={'id': '99590280-2f84-11ee-915b-5715b2447de4', 'date': '2023-07-31 11:28:25+0320', 'source': '/Users/avtharsewrathan/sideprojects2023/timescaleai/tsv-langchain/langchain/docs/docs/modules/ts_git_log.json', 'seq_num': 76, 'author_name': 'Markus Engel', 'commit_hash': ' 5cf354e2469ee7e43248bed382a4b49fc7ccfecd', 'author_email': '[email protected]'}),
Document(page_content='{"commit": " 88aaf23ae37fe7f47252b87325eb570aa417c607", "author": "noctarius aka Christoph Engelbert<[email protected]>", "date": "Wed Jul 12 14:53:40 2023 +0200", "change summary": "Allow Replica Identity (Alter Table) on CAGGs (#5868)", "change details": "This commit is a follow up of #5515, which added support for ALTER TABLE\\r ... REPLICA IDENTITY (FULL | INDEX) on hypertables.\\r \\r This commit allows the execution against materialized hypertables to\\r enable update / delete operations on continuous aggregates when logical\\r replication in enabled for them."}', metadata={'id': '1fcfa200-20b3-11ee-9a18-370561c7cb1a', 'date': '2023-07-12 14:53:40+0320', 'source': '/Users/avtharsewrathan/sideprojects2023/timescaleai/tsv-langchain/langchain/docs/docs/modules/ts_git_log.json', 'seq_num': 96, 'author_name': 'noctarius aka Christoph Engelbert', 'commit_hash': ' 88aaf23ae37fe7f47252b87325eb570aa417c607', 'author_email': '[email protected]'}),
Document(page_content='{"commit": " d5268c36fbd23fa2a93c0371998286e8688247bb", "author": "Alexander Kuzmenkov<[email protected]>", "date": "Fri Jul 28 13:35:05 2023 +0200", "change summary": "Fix SQLSmith workflow", "change details": "The build was failing because it was picking up the wrong version of Postgres. Remove it. "}', metadata={'id': 'cc0fba80-2d3a-11ee-ae7d-36dc25cad3b8', 'date': '2023-07-28 13:35:05+0320', 'source': '/Users/avtharsewrathan/sideprojects2023/timescaleai/tsv-langchain/langchain/docs/docs/modules/ts_git_log.json', 'seq_num': 82, 'author_name': 'Alexander Kuzmenkov', 'commit_hash': ' d5268c36fbd23fa2a93c0371998286e8688247bb', 'author_email': '[email protected]'}),
Document(page_content='{"commit": " 61c288ec5eb966a9b4d8ed90cd026ffc5e3543c9", "author": "Lakshmi Narayanan Sreethar<[email protected]>", "date": "Tue Jul 25 16:11:35 2023 +0530", "change summary": "Fix broken CI after PG12 removal", "change details": "The commit cdea343cc updated the gh_matrix_builder.py script but failed to import PG_LATEST variable into the script thus breaking the CI. Import that variable to fix the CI tests. "}', metadata={'id': 'd3835980-2ad7-11ee-b98d-c4e3092e076e', 'date': '2023-07-25 16:11:35+0850', 'source': '/Users/avtharsewrathan/sideprojects2023/timescaleai/tsv-langchain/langchain/docs/docs/modules/ts_git_log.json', 'seq_num': 84, 'author_name': 'Lakshmi Narayanan Sreethar', 'commit_hash': ' 61c288ec5eb966a9b4d8ed90cd026ffc5e3543c9', 'author_email': '[email protected]'})]
# This example specifies a query and a LIMIT value
retriever.invoke("What are two commits about hierarchical continuous aggregates?")
query='hierarchical continuous aggregates' filter=None limit=2
[Document(page_content='{"commit": " 35c91204987ccb0161d745af1a39b7eb91bc65a5", "author": "Fabr\\u00edzio de Royes Mello<[email protected]>", "date": "Thu Nov 24 13:19:36 2022 -0300", "change summary": "Add Hierarchical Continuous Aggregates validations", "change details": "Commit 3749953e introduce Hierarchical Continuous Aggregates (aka Continuous Aggregate on top of another Continuous Aggregate) but it lacks of some basic validations. Validations added during the creation of a Hierarchical Continuous Aggregate: * Forbid create a continuous aggregate with fixed-width bucket on top of a continuous aggregate with variable-width bucket. * Forbid incompatible bucket widths: - should not be equal; - bucket width of the new continuous aggregate should be greater than the source continuous aggregate; - bucket width of the new continuous aggregate should be multiple of the source continuous aggregate. "}', metadata={'id': 'c98d1c00-6c13-11ed-9bbe-23925ce74d13', 'date': '2022-11-24 13:19:36+-500', 'source': '/Users/avtharsewrathan/sideprojects2023/timescaleai/tsv-langchain/langchain/docs/docs/modules/ts_git_log.json', 'seq_num': 446, 'author_name': 'Fabrízio de Royes Mello', 'commit_hash': ' 35c91204987ccb0161d745af1a39b7eb91bc65a5', 'author_email': '[email protected]'}),
Document(page_content='{"commit": " 3749953e9704e45df8f621607989ada0714ce28d", "author": "Fabr\\u00edzio de Royes Mello<[email protected]>", "date": "Wed Oct 5 18:45:40 2022 -0300", "change summary": "Hierarchical Continuous Aggregates", "change details": "Enable users create Hierarchical Continuous Aggregates (aka Continuous Aggregates on top of another Continuous Aggregates). With this PR users can create levels of aggregation granularity in Continuous Aggregates making the refresh process even faster. A problem with this feature can be in upper levels we can end up with the \\"average of averages\\". But to get the \\"real average\\" we can rely on \\"stats_aggs\\" TimescaleDB Toolkit function that calculate and store the partials that can be finalized with other toolkit functions like \\"average\\" and \\"sum\\". Closes #1400 "}', metadata={'id': '0df31a00-44f7-11ed-9794-ebcc1227340f', 'date': '2022-10-5 18:45:40+-500', 'source': '/Users/avtharsewrathan/sideprojects2023/timescaleai/tsv-langchain/langchain/docs/docs/modules/ts_git_log.json', 'seq_num': 470, 'author_name': 'Fabrízio de Royes Mello', 'commit_hash': ' 3749953e9704e45df8f621607989ada0714ce28d', 'author_email': '[email protected]'})]
5. 使用现有的 TimescaleVector 向量存储
在上面的示例中，我们从文档集合中创建了一个向量存储。但是，我们经常希望将数据插入到现有向量存储中并从中查询数据。让我们看看如何在 TimescaleVector 向量存储中初始化、添加文档到以及查询现有文档集合。
要使用现有的 Timescale Vector 存储，我们需要知道要查询的表的名称 (COLLECTION_NAME) 和云 PostgreSQL 数据库的 URL (SERVICE_URL)。
# Initialize the existing
COLLECTION_NAME = "timescale_commits"
embeddings = OpenAIEmbeddings()
vectorstore = TimescaleVector(
collection_name=COLLECTION_NAME,
service_url=SERVICE_URL,
embedding_function=embeddings,
)
要将新数据加载到表中，我们使用 add_document() 函数。此函数接收文档列表和元数据列表。元数据必须包含每个文档的唯一 ID。
如果你希望文档与当前日期和时间相关联，则无需创建 ID 列表。将为每个文档自动生成 uuid。
如果你希望文档与过去的日期和时间相关联，可以使用 timecale-vector Python 库中的 uuid_from_time 函数创建 ID 列表，如上面的第 2 节所示。此函数接收一个日期时间对象并返回一个 uuid，其中日期和时间编码在 uuid 中。
# Add documents to a collection in TimescaleVector
ids = vectorstore.add_documents([Document(page_content="foo")])
ids
['a34f2b8a-53d7-11ee-8cc3-de1e4b2a0118']
# Query the vectorstore for similar documents
docs_with_score = vectorstore.similarity_search_with_score("foo")
docs_with_score[0]
(Document(page_content='foo', metadata={}), 5.006789860928507e-06)
docs_with_score[1]
(Document(page_content='{"commit": " 00b566dfe478c11134bcf1e7bcf38943e7fafe8f", "author": "Fabr\\u00edzio de Royes Mello<[email protected]>", "date": "Mon Mar 6 15:51:03 2023 -0300", "change summary": "Remove unused functions", "change details": "We don\'t use `ts_catalog_delete[_only]` functions anywhere and instead we rely on `ts_catalog_delete_tid[_only]` functions so removing it from our code base. "}', metadata={'id': 'd7f5c580-bc4f-11ed-9712-ffa0126a201a', 'date': '2023-03-6 15:51:03+-500', 'source': '/Users/avtharsewrathan/sideprojects2023/timescaleai/tsv-langchain/langchain/docs/docs/modules/ts_git_log.json', 'seq_num': 285, 'author_name': 'Fabrízio de Royes Mello', 'commit_hash': ' 00b566dfe478c11134bcf1e7bcf38943e7fafe8f', 'author_email': '[email protected]'}),
0.23607668446580354)
删除数据
你可以按 uuid 或按元数据上的过滤器删除数据。
ids = vectorstore.add_documents([Document(page_content="Bar")])
vectorstore.delete(ids)
True
如果要定期更新从特定来源或特定日期或某些其他元数据属性抓取的信息，则使用元数据进行删除特别有用。
vectorstore.add_documents(
[Document(page_content="Hello World", metadata={"source": "www.example.com/hello"})]
)
vectorstore.add_documents(
[Document(page_content="Adios", metadata={"source": "www.example.com/adios"})]
)
vectorstore.delete_by_metadata({"source": "www.example.com/adios"})
vectorstore.add_documents(
[
Document(
page_content="Adios, but newer!",
metadata={"source": "www.example.com/adios"},
)
]
)
['c6367004-53d7-11ee-8cc3-de1e4b2a0118']
覆盖向量存储
如果你有一个现有的集合，可以通过执行 from_documents 并设置 pre_delete_collection = True 来覆盖它
db = TimescaleVector.from_documents(
documents=docs,
embedding=embeddings,
collection_name=COLLECTION_NAME,
service_url=SERVICE_URL,
pre_delete_collection=True,
)
docs_with_score = db.similarity_search_with_score("foo")
docs_with_score[0]