Timeline for Why wouldnt Mysql use index on the Primary query in a nested query

13 events

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Oct 28, 2020 at 12:08	comment	added	Rich S		I've got the same quirk in my query - rather than using the list of IDs I'm generating in my sub-query to utilise the index, it just does a full table scan. However, it just occurred to me that it might be deciding this based on the fact that the sub-query could be returning 100s of IDs, and then it might actually be more efficient to do a table scan, rather than looking up each individual ID in the index.
Dec 2, 2014 at 13:58	answer	added	ypercubeᵀᴹ		timeline score: 6
Dec 2, 2014 at 12:59	vote	accept	tarni sharma
Dec 2, 2014 at 13:00
Dec 2, 2014 at 12:22	history	tweeted			twitter.com/#!/StackDBAs/status/539756385354141696
Dec 2, 2014 at 11:44	history	edited	tarni sharma	CC BY-SA 3.0	added 2342 characters in body
Dec 2, 2014 at 11:35	history	edited	tarni sharma	CC BY-SA 3.0	added 2342 characters in body
Dec 2, 2014 at 9:50	answer	added	jynus		timeline score: 7
Dec 2, 2014 at 9:48	comment	added	tarni sharma		yes they are the same type varchar(100)
Dec 2, 2014 at 9:47	history	edited	ypercubeᵀᴹ	CC BY-SA 3.0	edited tags
Dec 2, 2014 at 9:43	history	edited	tarni sharma	CC BY-SA 3.0	deleted 130 characters in body
Dec 2, 2014 at 9:39	history	edited	ypercubeᵀᴹ	CC BY-SA 3.0	added 154 characters in body
Dec 2, 2014 at 9:37	review	First posts
Dec 2, 2014 at 9:57
Dec 2, 2014 at 9:34	history	asked	tarni sharma	CC BY-SA 3.0