> 40708acd6 added code to have EXPLAIN ANALYZE show the memory or disk > usage for Material nodes.
You mean 1eff8279d? > This isn't quite right as if the material > node is rescanned, tuplestore_end() is called and that will result in > the memory usage for that scan being forgotten. What EXPLAIN reports > is the memory used by the final Material rescan. If that's > significantly less than some other rescan, then that's misleading. > > The fix is fairly simple, just use tuplestore_clear() instead of > tuplestore_end(). The existing code seems to handle no longer > NULLifying the tuplestore due to the tuplestore_ateof() check. The patch looks good to me. > The misreporting of the storage likely isn't a big deal. I suspect > rescans of Material nodes are not massively common, so maybe it's not > worth backpatching a fix. I have no evidence but I feel same as you (rescans of Material nodes are not massively common). Probably it's not worth backpatching. If we need backpatching, we could do it later. Regards, -- Tatsuo Ishii SRA OSS K.K. English: http://www.sraoss.co.jp/index_en/ Japanese:http://www.sraoss.co.jp
