You should run your queries and take a look at the query plans being used. It may be possible that your indexes are not being used as you think. See
http://db.apache.org/derby/docs/10.10/tuning/index.html the section on "How you use the RUNTIMESTATISTICS attribute” Possibly the statistics used by the optimizer are not up to date. Initially when an index is created and if the table is empty, no statistics are created for the index and subsequently the optimizer may not choose to use the index even though later there may be many rows in the table and the index may be the preferred mechanism. Also take a look at "Selectivity and cardinality statistics” and especially how to update the statistics in http://db.apache.org/derby/docs/10.10/ref/index.html for the “SYSCS_UTIL.SYSCS_UPDATE_STATISTICS” function. Also look to see if the index statistics daemon is enabled. Look at the “derby.storage.indexStats.auto” property. > On Feb 5, 2016, at 7:22 AM, kosurusekhar <kosurusek...@gmail.com> wrote: > > Hi All, > > We are having three schemas with almost same table structure, indexes, > queries, stored procedures in one database. But in one schema we are facing > some performance issue. We are having same index names and table names in > all schemas. In another schemas it is running without any problem. In one > schema with basic load only application is becoming slow. > > Is there any relationship with table names and index names with multiple > schemas? What ever we have queries/stored procedure's with performance > issues, these queries/stored procedure's running with out any issue in > another schema's. I am not understanding what is going wrong. > > I could see some times single transaction is locking couple of tables more > than once and not releasing. At this point of time we are feeling the > slowness. > > Please help me with some points to sort out this situation. > > Thanks in advance. > > Regards > Sekhar. > > > > -- > View this message in context: > http://apache-database.10148.n7.nabble.com/Performance-issue-with-same-index-name-in-multiple-schemas-tp145507.html > Sent from the Apache Derby Users mailing list archive at Nabble.com. Canoga Perkins 20600 Prairie Street Chatsworth, CA 91311 (818) 718-6300 This e-mail and any attached document(s) is confidential and is intended only for the review of the party to whom it is addressed. If you have received this transmission in error, please notify the sender immediately and discard the original message and any attachment(s).
