Configure connection pooling for `msodbc`

[dhirschfeld]

Configuring pyodbc.pooling = True doesn't work for unixodbc (i.e. linux)

• https://github.com/mkleehammer/pyodbc/wiki/The-pyodbc-Module#pooling
• https://github.com/mkleehammer/pyodbc/issues/774#issuecomment-1269852245

..therefore need to configure odbcinst.ini:

The only way to control pooling with unixodbc is to use odbcinst.ini:

• Pooling : global
• CPTimeout: driver
• PoolMaxSize: global
• PoolWaitTimeout: global

[dhirschfeld]

Pooling is enabled by editing the odbcinst.ini config file, and as such is enabled on a per driver basis. if its required to have some connections to a driver pooled and some not, then create two entries for the driver, and map different DSN's to the drivers. The setup to enable a pooled connection, would look like this...

[ODBC]
Trace       = No
Trace File      = /tmp/sql.log
Pooling = Yes

[INTERBASE-P] Description = Easysoft Driver for Interbase Driver = /usr/local/lib/libib6odbc.so Setup = /usr/local/lib/libib6odbcS.so FileUsage = 1 DontDLClose = 1 CPTimeout = 120

[INTERBASE] Description = Easysoft Driver for Interbase Driver = /usr/local/lib/libib6odbc.so Setup = /usr/local/lib/libib6odbcS.so FileUsage = 1 DontDLClose = 1

* http://www.unixodbc.org/doc/conn_pool.html

[dhirschfeld]

• https://github.com/lurcher/unixODBC/blob/3990a80a66cb3fdd463215590076048122bbe270/DriverManager/SQLAllocHandle.c#L296-L327
• https://github.com/lurcher/unixODBC/blob/3990a80a66cb3fdd463215590076048122bbe270/DriverManager/SQLConnect.c#L1042-L1050