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known_issues:very_slow_queries_on_mdb

Very Slow Queries on MDB

Symptom:

Queries or Automation Actions that run on specific tables may take several seconds, minutes, or even seem to freeze ClayCentral for a few minutes when the database is MDB.

MDB performs badly when queries become too complex and there are many records and/or joins. For example:

  • Queries on tables with 100,000s or 1,000,000s of records.
  • Queries on tables with 10,000s of records and over 15 linked fields.
  • Queries with multiple columns and filters from multiple tables, causing complex joins between numerous tables, some of them with 10,000s of records.
  • Analysis queries with over 10 indicators and 10,000s of records.

Solutions:

Adding filters, adding indexes, removing query columns or indicators, and deleting unneeded linked fields usually helps. See also Increasing Digital-Clay Performance for tips that may help in specific scenarios.

If queries still run slow after the above tips, then the only solution is to move to SQL Server.

known_issues/very_slow_queries_on_mdb.txt ยท Last modified: 2014/05/24 06:13 by 209.126.99.133

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