Re: Table as fifo
Posted by:
Rick James
Date: November 18, 2010 12:01AM
This cannot use the index: DATEDIFF('[timeisnowinstring]',C4) > 30
This can: C4<'[timeisbeforeonmonthstring]'
This costs a lot; get rid of it: C4!=0 AND
Not because it is hard to compute, but because it distracts from a simple scan of
INDEX(C4).
This is wh we use ramdisk -- Wrong! The CPU has to copy from "ram" to/from "ramdisk". With a decent sized key_buffer, you avoid these copies.
Yes, I should have said C2, not C4:
`C2` int(11) DEFAULT NULL COMMENT '',
If it can never be NULL, then say
`C2` int(11) DEFAULT NOT NULL COMMENT '',
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