Yes, a limit should speed up your query from the sounds of things.
From: Anibal David Acosta [mailto:aa@xxxxxxxxxxxx]
Is a table with 10 million of rows with a primary key but conditions used in select are not part of PK.
My table is like this: Column 1 ? PK Column 2 ? Indexed Column 3 ? Indexed
Column 2 and Column 3 are Indexed in the same index but they are not mark as unique or PK
The Query is like this: Select column1 from myTable where Column2 between X and Y
I am expecting just one record
De: Michael Holt [mailto:michael@xxxxxxx]
This really depends on the type of query you?re talking about. If there?s only one row in the table you?re querying then no, I don?t think it?ll change anything. If you?re querying a single row using a primary key it shouldn?t change anything. If you?re doing an aggregate query, say a sum of a bunch of rows, it also won?t improve performance.
If you?re doing a query on a table with multiple rows and not filtering by a primary key or other unique index then yes, it will improve the query.
From: pgsql-admin-owner@xxxxxxxxxxxxxx [mailto:pgsql-admin-owner@xxxxxxxxxxxxxx] On Behalf Of Anibal David Acosta
Hi I really like to do efficient SQL queries so, my question is if I am expecting no more than one row from a select, using the LIMIT 1 could improve the performance?
If I use my logic, the LIMIT 1 instruction tell to postgres that stop searching when found 1 record, but maybe it is unnecessary
Thanks
Anibal |
