Kbase P27171: Performance issues accessing the Database over JDBC using 'IN' predicate and ROWID.
| Autor |
Progress Software Corporation - Progress |
| Acesso |
Público |
| Publicação |
11/19/2009 |
|
Status: Unverified
SYMPTOM(s):
Performance issues accessing the Database over JDBC using 'IN' predicate and ROWID.
A 'SELECT' statement scans the entire table rather than using the ROWID index.
SELECT * FROM <table> WHERE ROWID IN (123456) - scans the whole table.
SELECT * FROM <table> WHERE ROWID = 123456 - uses ROWID index.
CAUSE:
The SQL optimizer requires that ROWID be used with an equality ("=") predicate in order to get direct access to a row via dbkey.
If the ROWID is not used with "=", then the predicate is evaluated record by record as data is read.
FIX:
None at this time