Thread: Large Tables/clustering/terrible performance of Postgresql

Hi,

Why does Postgres have such poor response times on LIKE queries.

In my database I have 1 table of 3.5 million rows.  I try the follogin search

select * from table1 where name like 'SMITH, JO%';


this query takes 1:30 seconds to return the matching row.

I have physically order the table by name and added an index to name and performed a vacuum analyze to see if that
helps. but still 1:30 for a result. 

I have built the same setup on a MS SQL Server database and get response times of 1 to 2 seconds for the same query.


Any tips suggestions etc.. would be appreciated

Michael McAlpine

On Mon, 31 Dec 2001, Michael McAlpine wrote:

> Hi,
>
> Why does Postgres have such poor response times on LIKE queries.
>
> In my database I have 1 table of 3.5 million rows.  I try the follogin search
>
> select * from table1 where name like 'SMITH, JO%';
>
>
> this query takes 1:30 seconds to return the matching row.
>
> I have physically order the table by name and added an index to name
> and performed a vacuum analyze to see if that helps.  but still 1:30
> for a result.
>
> I have built the same setup on a MS SQL Server database and get
> response times of 1 to 2 seconds for the same query.

What does explain say?


-jwb