[DERBY-1996] DatabaseMetaData.getColumns() takes long time to return columns for a particular schema of Apache JDO TCK

• Type: Improvement
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 10.2.1.6
• Component/s: SQL
• Labels: derby_triage10_11
• Urgency: Normal
• Issue & fix info: Repro attached
• Bug behavior facts: Performance
• Assignee: Unassigned
• Reporter: Andy Jefferson
• Created: 24/Oct/06 18:30
• Updated: 19/Apr/18 15:33

Description

When running the Apache JDO "TCK", JPOX needs to query the columns for a particular schema, and so uses DatabaseMetaData.getColumns(null, schemaName, null, null). This takes the order of 3 minutes on a dual-core Pentium 3GHz (with large ram). I've cut the JPOX part down to a stand-alone test (will attach it).

Thing to note is that with only the schema files d_* installed it takes the order of 20secs. When the schema_* files are also installed then performance goes downhill fast (even though they are in different schemas ... all *.sql file represents a different schema). No point in me postulating what could be the issue since you guys are the Derby experts.

Issue Links

• is related to: DERBY-2584 Creating a database with JPOX SchemaTool sometimes gives ArrayIndexOutOfBoundsException when getIndexInfo() is called