Re: how to improve "select num from telebook where num like '%345%'"

You don't say what version...
If 8.1.x, introduce a function based index for a function that will return the middle portion of a phone#. instr pops to mind.

BTW, what significance has the middle part of a telephone#? Weren't you told *not* to code information into unique identifiers?

--
Frank
<qiangye_at_my-deja.com> schreef in berichtnieuws
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> We have a huge table storing all of the telephone numbers of the city.

> The query is to retrieve all the numbers which contain "345" in the

> middle position. The current performance is too slow. Anybody knows how

> to improve the performance like that query?

>

> Thanks in advance!

>

>

>

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