Re: Duplicate data even with primary keys enabled

Hi Teja,

Your columns are varchar. They may seem the same to you due to the tool you
use. But, it doesn't mean they are identical. There can be leading or
trailing spaces.

You can test the data on columns by md5 hashing function, example below. If
their hashes are the same, it means there is a problem on the database
side. Otherwise, the problem comes from the data itself or from the
application writing the data into the table.

*select md5(col1), md5(col2), md5(col3) from table.*

Another possibility is that you hit a bug I mentioned earlier from 14.0 to
14.3.
- What version of PpstgreSQL do you use?
- Did you use CONCURRENTLY keyword while creating your index?

Best regards.
Samed YILDIRIM

On Fri, 28 Oct 2022, 23:16 Teju Jakkidi vlogs, <teja(dot)jakkidi05(at)gmail(dot)com>
wrote:

> Hello Jakobs,
>
> I have provided the sample create table and inserts that we are observing.
>
> CREATE TABLE IF NOT EXISTS "TEST"
> (
> "COL1" character varying(9) COLLATE pg_catalog."default" NOT NULL,
> "COL2" character varying(30) COLLATE pg_catalog."default" NOT NULL,
> "COL3" character varying(30) COLLATE pg_catalog."default" NOT NULL,
> "COL4" numeric(10,0) NOT NULL,
> "COL5" character varying(12) COLLATE pg_catalog."default" NOT NULL,
> "COL6" character varying(12) COLLATE pg_catalog."default" NOT NULL,
> CONSTRAINT test_pk PRIMARY KEY ("COL1", "COL2", "COL3")
> )
>
> CREATE UNIQUE INDEX IF NOT EXISTS "TEST_UNIQUE"
> ON "TEST" USING btree
> ("COL1" COLLATE pg_catalog."default" ASC NULLS LAST, "COL2" COLLATE
> pg_catalog."default" ASC NULLS LAST, "COL3" COLLATE pg_catalog."default"
> ASC NULLS LAST);
>
> CREATE INDEX IF NOT EXISTS "TEST_INDEX"
> ON "TEST" USING btree
> ("COL1" COLLATE pg_catalog."default" ASC NULLS LAST, "COL3" COLLATE
> pg_catalog."default" ASC NULLS LAST);
>
> *Also, the values that we are seeing is as below:*
>
> COL1 COL2 COL3 COL4 COL5 COL6
> 1 3456 76542 5 ABC 1234
> 1 3456 76542 5 ABC 1234
> 2 9872 89765 0 FGT 1234
> 3 6547 78659 7 JHL 8790
>
> We already defined COL1, COL2, COL3 as primary keys, but still as you see
> above in the table output, the first 2 rows has exactly same combination
> for those 3 rows.
>
> Thanks,
> Teja.
>
>
> On Fri, Oct 28, 2022 at 11:41 AM Holger Jakobs <holger(at)jakobs(dot)com> wrote:
>
>>
>> Am 28.10.22 um 20:27 schrieb Teja Jakkidi:
>> > Hi YILDIRIM,
>> >
>> > Thanks for your response.
>> >
>> > We have a composite primary key on 3columns. We are noticing multiple
>> > rows with same values in the 3pk columns which should not happen as
>> > primary constraint is defined on them.
>> > Also, none of the columns are null.
>> >
>> > Regards,
>> > Teja. J.
>> >
>> Unless you don't post your CREATE TABLE command plus some INSERT command
>> which lead to the described behavior, we won't be able to track the
>> problem.
>>
>>
>> --
>> Holger Jakobs, Bergisch Gladbach, Tel. +49-178-9759012
>>
>>