Server crash when using duplicate segmentby column
The segmentby column info array is populated by using the column
attribute number as an array index. This is done as part of validating
and creating segment by column info in function `compresscolinfo_init`.
Since the column is duplicated the attribute number for both the
segmentby column is same. When this attribute number is used as an
index, only one of the array element is populated correctly with the
detailed column info whareas the other element of the array ramins
NULL. This segmentby column info is updated in catalog as part of
processing compression options (ALTER TABLE ...).
When the chunk is being compressed this segmentby column information is
being retrieved from the catalog to create the scan key in order to
identify any existing index on the table that matches the segmentby
column. Out of the two keys one key gets updated correctly whereas the
second key contains NULL values. This results into a crash during index
scan to identify any existing index on the table.
The proposed change avoid this crash by raising an error if user has
specified duplicated columns as part of compress_segmentby or
compress_orderby options.
Also, added postgresql-client package in linux-32bit build dependencies
to avoid failure as part of uploading the regression results.
ef783c4b55