Improve Seq scan performance

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Dear List,

I would like to improve seq scan performance. :-)

I have many cols in a table. I use only 1 col for search on it. It is indexed with btree with text_pattern_ops. The search method is: r like '%aaa%' When I make another table with only this col values, the search time is better when the data is cached. But wronger when the data isn't in cache.

I think the following:
- When there is a big table with many cols, the seq search is read all cols not only searched. - If we use an index with full values of a col, it is possible to seq scan over the index is make better performance (lower io with smaller data).

It is possible to make an index on the table, and make a seq index scan on this values?

Thanks for helping.

Best Regards,
   Ferenc

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