Many Merge/Read SQL operations inside one transaction raise exception that temp table already exists

[dimonchelli-dev]

Version:
Problem was discovered due to version update from 6.5.6 to 8.0.2

Problem:
If we have many Merge/Read operations with the same entity type inside one transaction, then an exception will occur.
Microsoft.Data.SqlClient.SqlException (0x80131904): There is already an object named '#SomeEntityTemp' in the database
Config:

BulkConfig
{
    ...
    UseTempDB=true,
    UniqueTableNameTempDb=false,
    ...
}

Reason:
Some optimizations were done in code not to do extra db query execution call in case of usage of temp db.
It didn't work properly in case of multiple requests for entities of same type with config above because temp table name generation depends on entity type.
The possible solution is to use UniqueTableNameTempDb=true, but it is not optimal due to SQL Server query plan caching.

EFCore.BulkExtensions/EFCore.BulkExtensions/SqlAdapters/SqlServer/SqlServerAdapter.cs

Line 245 in 7feed45

if (!tableInfo.BulkConfig.UseTempDB) // When UseTempDB is set temp tables are automaticaly dropped by Db

EFCore.BulkExtensions/EFCore.BulkExtensions/SqlAdapters/SqlServer/SqlServerAdapter.cs

Line 358 in 7feed45

if (!tableInfo.BulkConfig.UseTempDB)

and maybe in other adapters