who can tell me why?why i can't query two table

feelfly · #1 (**permalink**) 12-23-03, 02:12

i have explain my select sql as follows:
explain select * from a, b where a.reporttime = b.reporttime;½á¹ûÈçÏÂ
table type possible_keys key key_len ref rows extra
b all reporttime null null null 170943
a ref reporttime reporttime 8 b.reporttime 303
when i execute" explain select * from a, b where a.reporttime = b.reporttime" my pc will die.
and actually b table has more data than 303 rows.reporttime has been indexed .who can tell me why?

ika · #2 (**permalink**) 12-27-03, 03:12

Quote:

Originally posted by feelfly
i have explain my select sql as follows:
explain select * from a, b where a.reporttime = b.reporttime;½á¹ûÈçÏÂ
table type possible_keys key key_len ref rows extra
b all reporttime null null null 170943
a ref reporttime reporttime 8 b.reporttime 303
when i execute" explain select * from a, b where a.reporttime = b.reporttime" my pc will die.
and actually b table has more data than 303 rows.reporttime has been indexed .who can tell me why?

No OS, no version of MySQL etc. and my crystal ball is broken

feelfly · #3 (**permalink**) 12-27-03, 04:04

win2000+mysql4.016

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