tablesample clause doesnt support to be applied to subquery.

Started by Windover 3 years ago2 messagesgeneral
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#1Wind
guolipengyeah@126.com

hi~
I test "tablesample" feature on pg9.5 and found that tablesample doesnt support to be applied to subquery.
for example this sql doesnt work on pg9.5:
```
create table t1(
c1 int,
c2 int
);
select c2 from (select * from t1) as t2 tablesample system (50);
```
while i read sql2003 standard about tablesample and think it should allow this usage according to standard.
is it a deviation to sql standard?

#2rob stone
floriparob@tpg.com.au
In reply to: Wind (#1)
Re: tablesample clause doesnt support to be applied to subquery.

Hello,

On Mon, 2022-08-08 at 15:52 +0800, Wind wrote:

hi~
I test "tablesample" feature on pg9.5 and found that tablesample
doesnt support to be applied to subquery.
for example this sql doesnt work on pg9.5:
```
create table t1(
    c1 int,
    c2 int
);
select c2 from (select * from t1) as t2 tablesample system (50);
```
while i read sql2003 standard about tablesample and think it should
allow this usage according to standard.
is it a deviation to sql standard?

Version 9.5 is not supported. The oldest supported version is 10, the
current version is 14.

Please read chapter 58 in the doco.

HTH,