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WM_CONCAT

2 articles · Page 1 of 1

Nov 5, 2024 · Databases

Using WM_CONCAT in OceanBase 3.x: Restoring Order with NO_REWRITE Hint

This article explains how to replace Oracle's XMLAGG with OceanBase's WM_CONCAT, analyzes why the result order is lost in OceanBase 3.x, demonstrates reproduction steps, shows that adding a NO_REWRITE hint restores ordering, and provides the final SQL solution and notes for OceanBase 4.x.

Database MigrationHintOceanBase

0 likes · 9 min read

Using WM_CONCAT in OceanBase 3.x: Restoring Order with NO_REWRITE Hint

dbaplus Community

Sep 11, 2017 · Databases

How I Turned a Half‑Hour Oracle WM_CONCAT Query into a 3‑Second Execution

This article recounts a real‑world Oracle SQL performance case where a slow WM_CONCAT‑based query took over 30 minutes, the root cause was identified, and a rewritten SQL using window functions and proper aggregation reduced execution time to under three seconds.

OracleQuery TuningSQL

0 likes · 13 min read

How I Turned a Half‑Hour Oracle WM_CONCAT Query into a 3‑Second Execution