Erroneous behavior of primary key - Mailing list pgsql-general

From Daniel J Peacock
Subject Erroneous behavior of primary key
Date
Msg-id CAPQSkmPR82gk9RRH8TZjCYzXpNZUyeP4_=nbPdi5qStySoQGJg@mail.gmail.com
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Responses Re: Erroneous behavior of primary key
Re: Erroneous behavior of primary key
List pgsql-general
Good afternoon, all.
I've got an odd situation with a table that has a varchar(255) as the primary key that is getting key values from an Elasticsearch engine.  What I'm finding is that even though there is a primary key on the table, I am getting duplicated keys in the data and the constraint is not blocking these.  When I do a "select <pk_field>,count(*) from <table> group by <pk_field> having count(*) > 1" I get no results.  Yet, when I search the table for a value that is like a key I know to be duplicated, I get multiple results.  When I select from the table where field is equal to the duplicated field I get one result.  I verified that they are distinct row with ctid.  I also created a clone of the table with CTAS and then tried to create a unique index on the id varchar field but that failed with "duplicate keys found".  I'm stumped as to what could be the problem.
The only thing that I can think of is that the primary key is somehow corrupt.  I've noticed this behavior on other tables on this database.  
What could be causing this sort of problem?

Thanks in advance for any insights.

Dan Peacock
Auto-wares, Inc.

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