Re: Avoiding table scans...

[Corrado Pandiani]

Il 24/07/14 11:57, Chris Knipe ha scritto:
 On Thu, Jul 24, 2014 at 11:47 AM, Johan De Meersman vegiv...@tuxera.be 
 wrote:
 - Original Message -
 From: Chris Knipe sav...@savage.za.org
 To: mysql@lists.mysql.com
 Sent: Thursday, 24 July, 2014 11:17:50 AM
 Subject: Avoiding table scans...

 mysql SELECT MIN(ArtNumber) AS ArtNumber, MessageID FROM
 78168ea0a9b3b513a1f2d39b559b406e WHERE ArtNumber  '2118806';
 You're putting quotes around ArtNumber in your where clause, where it really 
 is a bigint. Thus, you're forcing implicity conversion in the parser, 
 instead of simply doing an index lookup.

 mysql SELECT MIN(ArtNumber) AS ArtNumber, MessageID FROM
 78168ea0a9b3b513a1f2d39b559b406e WHERE ArtNumber  2118806;
 +---+---+
 | ArtNumber | MessageID |
 +---+---+
 |   2118807 | part26of79.GfYzwhqz$ORUpNi3tjsW@camelsystem-powerpost.local |
 +---+---+
 1 row in set (19.37 sec)

 mysql SELECT MIN(ArtNumber) AS ArtNumber, MessageID FROM
 78168ea0a9b3b513a1f2d39b559b406e WHERE ArtNumber  '2118806';
 +---+---+
 | ArtNumber | MessageID |
 +---+---+
 |   2118807 | part26of79.GfYzwhqz$ORUpNi3tjsW@camelsystem-powerpost.local |
 +---+---+
 1 row in set (19.43 sec)

 mysql EXPLAIN SELECT MIN(ArtNumber) AS ArtNumber, MessageID FROM
 78168ea0a9b3b513a1f2d39b559b406e WHERE ArtNumber  2118806;
 ++-+--+---+---+-+-+--+--+-+
 | id | select_type | table| type  |
 possible_keys | key | key_len | ref  | rows | Extra   |
 ++-+--+---+---+-+-+--+--+-+
 |  1 | SIMPLE  | 78168ea0a9b3b513a1f2d39b559b406e | range |
 PRIMARY   | PRIMARY | 8   | NULL | 31868953 | Using where |
 ++-+--+---+---+-+-+--+--+-+
 1 row in set (0.18 sec)


 Partitioning should help from what I am reading currently... Just not
 sure about a few things just yet.



Try this

SELECT ArtNumber, MessageID FROM 78168ea0a9b3b513a1f2d39b559b406e WHERE
ArtNumber=(SELECT MIN(ArtNumber) FROM 78168ea0a9b3b513a1f2d39b559b406e
WHERE ArtNumber2118806)


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Re: How to show highly frequent words in fulltext index ?

[Corrado Pandiani]

Yes,

you can use myisam_ftdump

Bye

On Thu, 23 Apr 2009 17:24:09 +0200, Sebastien Moretti
sebastien.more...@unil.ch wrote:
 Hi,
 
 Is there a command to see which words are highly frequent in a fulltext
 index ?
 
 Thanks
 
 --
 Sébastien Moretti
 
 
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Corrado Pandiani
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F.C.Internazionale Milano Spa


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Chinese charset

[Corrado Pandiani]

Is it possible to use MySQL with a chinese charset (utf8) ?

If not, what do you suggest to do if I want to develop a database for a
chinese web site ?

thanks


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