On 6 Oct 2006 22:32:16 -0700, ck <ck.karthic@xxxxxxxxx> wrote:
Hello, I am using PostgreSQL 7.3.2. I have a large table in a
that's very old... you should upgrade at least to 7.3.15
database , its primary key field is int8. Almost all of my queries are written relaing to that field. That field is B-Tree indexed. When i check the query plan i found that all the queries are using sequential scan and index was not used. So my queries are likely to be slow. But when i tried to convert the values given to that field to int8 in a where condition then the parser is using the index scan, Eg select * from h057 where h057001 = 1142::int8 the above query uses index scan select * from h057 where h057001 = 1142 the above query uses sequential scan.
that's because in 7.3 you must cast to the type of the indexed column in order to use the indexes... had you never seen this? TIP 9: In versions below 8.0, the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match upgrade -- regards, Jaime Casanova "Programming today is a race between software engineers striving to build bigger and better idiot-proof programs and the universe trying to produce bigger and better idiots. So far, the universe is winning." Richard Cook