我在我的后勤部中总是担心的一个事情是,我的密集地区将不足以储存必要的数据。 目前开展的PHP项目Im将需要储存地块,其长度可能因地而异。
我不熟悉MySQL如何储存数据,我很想知道,如果使用诸如<代码>TEXT等较大数据类型来进行可能少于100个特性的扼杀,是否会过于熟练。 我的SQL与像这种高度变化的数据有何关系?
See this: http://dev.mysql.com/doc/refman/5.1/en/storage-requirements.html。
VARCHAR(M), VARBINARY(M) L + 1 bytes if column values require 0 – 255 bytes, L + 2 bytes if values may require more than 255 bytes
BLOB, TEXT L + 2 bytes, where L < 2^16
因此,就最糟糕的情况而言,在使用TEXT时,你将每台电池再使用1台。
关于指数化:您可以,但你必须预留时间,例如。
CREATE INDEX part_of_name ON customer (name(10));
此外,如果使用MyISAM发动机,TEXT栏允许你制作和查询全文索引。
另一方面,科学文栏没有与表格一起储存,因此,从理论上讲,绩效在某些情况下可能成为一个问题(看你的具体案例)。
In recent versions of MySQL, VARCHAR fields can be quite long - up to 65,535 characters depending on character set and the other columns in the table. It is very efficient when you have varying length strings. See: http://dev.mysql.com/doc/refman/5.1/en/char.html
如果你需要比这更长时间的扼杀,那么你很可能不得不放弃和利用TEXT。
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