2014-07-19 6:26 GMT+08:00 Tom Lane <t...@sss.pgh.pa.us>: > =?UTF-8?B?5Zyf5Y2c55q/?= <pengcz.n...@gmail.com> writes: > > for studying polyphase merge algorithm of tuplesort.c, I use ddd and > > apend a table, which has a schema as follows: > > ... > > and has 36684 records, and every record is like: > > id code article name department > > 31800 266 \N Machault 77 > > > and for getting into external sort, I type the following command: > > > select * from towns order by name desc; > > > but I found it need not reach D5 and D6 during sorting, > > That doesn't sound like enough data to force it to spill to disk at all; > at least not unless you turn down work_mem to some very small value. > >
hi, Tom thanks a lot! > work_mem you said remind me one more thing I did, I tried to change BLCKSZ = 8192/2, and successfully compiled, but I got a error when executing initdb Dillon
