Have a question regarding when a Query Plan uses an Index.
I have a basic statement
This query uses the Index Scan: explain analyse select * from tablea where columna_id < 57
This query uses Seq Scan: explain analyse select * from tablea where columna_id < 58
There are about 5000 records in this table, and columna_id is the primary key, which is Indexed... And recently recreated.
OK - what does explain analyse say?
Each line will have two parts, the expected costs/number of rows and the actual time/number of rows.
If PG is expecting say 50 rows in the first query but 150 in the second then it might decide a sequential scan is quicker.
Post the outputs of explain analyse and we can compare them. -- Richard Huxton Archonet Ltd
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