Hello, just a little question, It's preferable to use Text Fields or
varchar(255) fields in a table? Are there any performance differences in the
use of any of them?

Thanks a lot for your answer!

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  • Steinar H. Gunderson at Oct 5, 2005 at 6:35 pm

    On Wed, Oct 05, 2005 at 12:21:35PM -0600, Cristian Prieto wrote:
    Hello, just a little question, It's preferable to use Text Fields or
    varchar(255) fields in a table? Are there any performance differences in the
    use of any of them?
    They are essentially the same. Note that you can have varchar without length
    (well, up to about a gigabyte or so after compression), and you can have
    varchar with a length well above 255 (say, 100000).

    /* Steinar */
  • Josh Berkus at Oct 5, 2005 at 6:56 pm
    Cristian,
    Hello, just a little question, It's preferable to use Text Fields or
    varchar(255) fields in a table? Are there any performance differences in
    the use of any of them?
    TEXT, VARCHAR, and CHAR use the same underlying storage mechanism. This
    means that TEXT is actually the "fastest" since it doesn't check length or
    space-pad. However, that's unlikely to affect you unless you've millions
    of records; you should use the type which makes sense given your
    application.

    For "large text fields" I always use TEXT. BTW, in PostgreSQL VARCHAR is
    not limited to 255; I think we support up to 1GB of text or something
    preposterous.

    --
    --Josh

    Josh Berkus
    Aglio Database Solutions
    San Francisco
  • Ahmad Fajar at Oct 10, 2005 at 11:24 am
    Dear Cristian,

    If you need to index the field, you must know that it limit the length up to
    1000 bytes. So if you need to index the field you must limit the field type,
    ex: varchar(250), than you can index the field and you can gain better
    perfomance in searching base on the fields, because the search uses the
    index you have been created.
    If you do not need to index the field, you can use the text field. Because
    text field can store data up to 4 Gbytes.

    Regards,
    ahmad fajar

    -----Original Message-----
    From: [email protected]
    On Behalf Of Cristian Prieto
    Sent: Kamis, 06 Oktober 2005 1:22
    To: [email protected]; [email protected]
    Subject: [PERFORM] Text/Varchar performance...

    Hello, just a little question, It's preferable to use Text Fields or
    varchar(255) fields in a table? Are there any performance differences in the
    use of any of them?

    Thanks a lot for your answer!


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  • Steinar H. Gunderson at Oct 10, 2005 at 12:54 pm

    On Mon, Oct 10, 2005 at 06:28:23PM +0700, Ahmad Fajar wrote:
    than you can index the field and you can gain better
    perfomance in searching base on the fields, because the search uses the
    index you have been created.
    That really depends on the queries. An index will help some queries (notably
    <, = or > comparisons, or LIKE 'foo%' with the C locale), but definitely not
    all (it will help you nothing for LIKE '%foo%').
    If you do not need to index the field, you can use the text field. Because
    text field can store data up to 4 Gbytes.
    So can varchar.

    /* Steinar */

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