[TAJO-2007] By default, Optimizer should use the table volume in TableStat.

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.12.0, 0.11.1
• Component/s: Planner/Optimizer
• Assignee: Hyunsik Choi
• Reporter: Hyunsik Choi
• Created: 03/Dec/15 07:49
• Updated: 28/Jan/16 17:27
• Resolved: 17/Dec/15 08:28

Description

Currently, the optimizer by default gets table volumes through storage manager and employ them for join optimization. But, in some cases, it causes performance degradation because aggregating all file volumes is not cheap in large partitioned tables on S3 or HDFS.

So, this patch improves TableStatUpdateRewriter to use table volumes of TableStat by default, and it also adds a session variable 'USE_TABLE_VOLUME' to allow the optimizer to use the table volume through storage handler.

Issue Links

• depends upon: TAJO-2005 Add TableStatUpdateRewriter