PERF: Optimize execute() hot path: soft reset, prepare caching, and guarded diagnostics

[bewithgaurav]

Work Item / Issue Reference

AB#44166

GitHub Issue: #<ISSUE_NUMBER>

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Summary

This pull request introduces performance benchmarking infrastructure improvements and optimizations to the mssql_python driver, as well as documentation and workflow updates to support a new PERF: pull request prefix. The most significant changes are grouped below.

Driver Performance Optimizations:

• Implemented a lightweight _soft_reset_cursor in cursor.py to reuse prepared statement handles, avoiding unnecessary SQLPrepare calls when executing the same SQL repeatedly. This improves performance for repeated statement execution. [1] [2] [3] [4]
• Optimized parameter conversion logic to skip redundant conversions when re-executing the same SQL with the same parameter style, further reducing overhead.
• Added a new DDBCSQLResetStmt binding in the C++ layer to support the lightweight reset operation, and exposed it to Python. [1] [2]

[github-actions]

📊 Code Coverage Report

🔥 Diff Coverage 87%

🎯 Overall Coverage 79%

📈 Total Lines Covered: 6787 out of 8540 📁 Project: mssql-python

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Diff Coverage

Diff: main...HEAD, staged and unstaged changes

• mssql_python/cursor.py (95.2%): Missing lines 1383
• mssql_python/pybind/ddbc_bindings.cpp (77.8%): Missing lines 1383-1384,1387-1388

Summary

• Total: 39 lines
• Missing: 5 lines
• Coverage: 87%

mssql_python/cursor.py

Lines 1379-1387

  1379         if reset_cursor:
  1380             if self.hstmt:
  1381                 self._soft_reset_cursor()
  1382             else:
! 1383                 self._reset_cursor()
  1384         else:
  1385             # Close just the ODBC cursor (not the statement handle) so the
  1386             # prepared plan can be reused.  SQLFreeStmt(SQL_CLOSE) releases
  1387             # the cursor associated with hstmt without destroying the

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mssql_python/pybind/ddbc_bindings.cpp

Lines 1379-1392

  1379 }
  1380 
  1381 SQLRETURN SQLResetStmt_wrap(SqlHandlePtr statementHandle) {
  1382     if (!SQLFreeStmt_ptr) {
! 1383         DriverLoader::getInstance().loadDriver();
! 1384     }
  1385     SQLHANDLE hStmt = statementHandle->get();
  1386     if (!hStmt) {
! 1387         return SQL_INVALID_HANDLE;
! 1388     }
  1389 
  1390     SQLRETURN rc = SQLFreeStmt_ptr(hStmt, SQL_CLOSE);
  1391     if (SQL_SUCCEEDED(rc)) {
  1392         rc = SQLFreeStmt_ptr(hStmt, SQL_RESET_PARAMS);

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📋 Files Needing Attention

📉 Files with overall lowest coverage (click to expand)

mssql_python.pybind.logger_bridge.cpp: 59.2%
mssql_python.pybind.ddbc_bindings.h: 67.8%
mssql_python.row.py: 70.5%
mssql_python.pybind.logger_bridge.hpp: 70.8%
mssql_python.pybind.ddbc_bindings.cpp: 74.6%
mssql_python.pybind.connection.connection.cpp: 75.8%
mssql_python.__init__.py: 77.3%
mssql_python.ddbc_bindings.py: 79.6%
mssql_python.pybind.connection.connection_pool.cpp: 79.6%
mssql_python.connection.py: 85.3%

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