Problem with query length - Mailing list pgsql-general

From Taravudh Tipdecho
Subject Problem with query length
Date
Msg-id 36EF3855.9A4D5B06@hpcc.nectec.or.th
Whole thread Raw
List pgsql-general
Hello

We have two different machines both running Red Hat 5.2, but one machine
has PostgreSQL version 6.3 while the other machine has PostgreSQL
version 6.4.2. Our problem is that we have a table which we want to
store political boundaries as polygons. Taking into account the 8K limit
per tuple and the storage space for a polygon (4 + 32n) we determined
that we can only store 255 points for each polygon. Therefore, we
ensured that all our polygons have less than 250 points.

Our problem is with the insert command when we insert a large polygon
(~200 points). With version 6.3 we have no problem inserting the
polygon. In fact all the polygons were inserted, verifying that they
were less than the 8K limit. However with version 6.4.2, the backend
closes the connection during the insert.

The first time we noticed this, we had a lot of trailing zeros on the
values of the points and eliminating the zeros allowed a smaller polygon
(that previously failed with ~ 170 points) to be inserted in version
6.4.2. This seems to indicate that there is some kind of limit on the
length of the query string. Isolating the query string that failed
indicates that the string is about 4500 bytes.

Does anyone have any idea what happened between 6.3 and 6.4.2 and what
we can do to solve this problem? We checked the archives but only found
references to the 8K limit. Any help would be greatly appreciated.

Thank you for your time and effort in this matter.

Best regards

Taravudh



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