| Title: | DEC Rdb against the World |
| Moderator: | HERON::GODFRIND |
| Created: | Fri Jun 12 1987 |
| Last Modified: | Thu Feb 23 1995 |
| Last Successful Update: | Fri Jun 06 1997 |
| Number of topics: | 1348 |
| Total number of notes: | 5438 |
INGRES has the ability for the application programmer to retrieve
information from distribution/cardinality lists. The benefit being
that this can give an indication of how big a query may be and allow
the programmer to put some conditions in before the fact of an actual
query. Do we have this capability in RDB???
Thank You,
Jerry
| T.R | Title | User | Personal Name | Date | Lines |
|---|---|---|---|---|---|
| 764.1 | GNPIKE::GUAY | Wed Oct 17 1990 21:38 | 20 | ||
Hi Jerry, RDB$CARDINALITY in the RDB$RELATIONS table contains the cardinality information for the table in RDB. For more information, see the RDO and RMU reference manual part 1, section 7.9 As an aside, my understanding is that the statistics that I think you are talking about with ingres are only updated when an optimizedb is run. So if you don't update your database very often by running optimizedb, the statistics would be stale. hope this helps, todd (what kinds of conditions are you trying to do with the cardinality info?) | |||||
| 764.2 | Query the system tables | TRCO01::MCMULLEN | Ken McMullen | Thu Oct 18 1990 14:45 | 7 |
Jerry,
Don't forget you can query RDB's systems tables in the same fashion
that you can query the data tables. This means you can query the
cardinality fields for each relation.
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