Help regarding performance connecting to MSSQL

[thematica]

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Example Code

from sqlalchemy import create_engine, text
import pyodbc
from sqlalchemy.engine import URL
from langchain_ollama import ChatOllama
from langchain_core.messages import AIMessage
from langchain_core.prompts import (SystemMessagePromptTemplate, HumanMessagePromptTemplate, ChatPromptTemplate)
from langchain_core.output_parsers import StrOutputParser
from langchain_community.utilities import SQLDatabase
from langchain_experimental.sql import SQLDatabaseChain

llm = ChatOllama(
    base_url="http://localhost:11434",
    model="deepseek-r1:8b",
    temperature=0
)

db = SQLDatabase.from_uri("mssql+pyodbc://readonly:password1@SQLSERVER/LOGS?driver=ODBC+Driver+18+for+SQL+Server&TrustServerCertificate=yes")
db_chain = SQLDatabaseChain.from_llm(llm=llm, db=db, verbose=True)

Description

i'm trying to learn how to code AI using python (never use this language before)
the code will try to connect to our production database which is very large (1.xTB data, hundreds of tables)

while the connection is created, but the code seems waiting something (didn't show the prompt)
i did check on the MSSQL side, it seems the session is scanning or reading something from the server?
i literally wait for 15 minutes before i give up and cancel the code (the connection on the server also closed)

i tried creating simple database LOGS with only 1 tables and 30 rows, it connect just fine

same code but with different database (this one is successfully connect and show the prompt)

db = SQLDatabase.from_uri("mssql+pyodbc://readonly:password1@SQLSERVER/LOGS?driver=ODBC+Driver+18+for+SQL+Server&TrustServerCertificate=yes")

anyone can help me on this?
Thank you very much

PS: i also tried simple connection from python to MSSQL using pyodbc
and it successfully connect and run the static query i put in the command (not AI related, just simple code to test connect python to MSSQL). so i don't think pyodbc or my SQL Server is the problem.

System Info

Windows 11
Python 3.12

[gmoe1994]

@thematica If you put: lazy_table_reflection=True as an argument to SQLDatabase.from_uri() it skips loading metadata about your database. It initializes in a few seconds now instead of over a minute for me.