On 6/17/23 02:02, Quan Zongliang wrote:
>
>
> On 2023/6/17 06:46, Tom Lane wrote:
>> Quan Zongliang writes:
>>> Perhaps we should discard this (dups cnt > 1) restriction?
>>
>> That's not going to happen on the basis of one test case that you
>> haven't even shown us. The implications of doing
On 6/17/23 00:32, Quan Zongliang wrote:
> ...
>
> It's not just a small table. If a column's value is nearly unique. It
> also causes the same problem because we exclude values that occur only
> once. samplerows <= num_mcv just solves one scenario.
> Perhaps we should discard this (dups cnt > 1) re
On 2023/6/17 06:46, Tom Lane wrote:
Quan Zongliang writes:
Perhaps we should discard this (dups cnt > 1) restriction?
That's not going to happen on the basis of one test case that you
haven't even shown us. The implications of doing it are very unclear.
In particular, I seem to recall tha
Quan Zongliang writes:
> Perhaps we should discard this (dups cnt > 1) restriction?
That's not going to happen on the basis of one test case that you
haven't even shown us. The implications of doing it are very unclear.
In particular, I seem to recall that there are bits of logic that
depend on
On 2023/6/16 23:39, Tomas Vondra wrote:
On 6/16/23 11:25, Quan Zongliang wrote:
We have a small table with only 23 rows and 21 values.
The resulting MCV and histogram is as follows
stanumbers1 | {0.08695652,0.08695652}
stavalues1 | {v1,v2}
stavalues2 |
{v3,v4,v5,v6,v7,v8,v9,v10,v11,v12,
On 6/16/23 11:25, Quan Zongliang wrote:
>
> We have a small table with only 23 rows and 21 values.
>
> The resulting MCV and histogram is as follows
> stanumbers1 | {0.08695652,0.08695652}
> stavalues1 | {v1,v2}
> stavalues2 |
> {v3,v4,v5,v6,v7,v8,v9,v10,v11,v12,v13,v14,v15,v16,v17,v18,v19,v
We have a small table with only 23 rows and 21 values.
The resulting MCV and histogram is as follows
stanumbers1 | {0.08695652,0.08695652}
stavalues1 | {v1,v2}
stavalues2 |
{v3,v4,v5,v6,v7,v8,v9,v10,v11,v12,v13,v14,v15,v16,v17,v18,v19,v20,v21}
An incorrect number of rows was estimated when
