Context:


Occasionally, we use SLONIK EXECUTE SCRIPT to create a table, and then add
it to replication by putting the new table in a temporary set and merging
it into our main set. The tables we create reference one of our
highest-activity tables, locations_miles_log, which regularly receives
hundreds of updates every few seconds.

We run Slony 2.0.7 and Postgresql 8.4.9 on a single-master, single-slave
cluster, connected by a fast WAN, with both slons running on the same
server as the slave.


Problem:


Recently, we created a table via SLONIK EXECUTE SCRIPT, with the following
structure (as reported by the slonik_execute_script altperl script):

    DDL script consisting of 1 SQL statements

    DDL Statement 0: (0,508) [CREATE TABLE display_field_data_23656(

                  miles_log_id integer NOT NULL,

                  locations_miles_log_id integer NOT NULL



                 ,CONSTRAINT display_field_data_23656_pkey PRIMARY KEY
(locations_miles_log_id)

                 ,CONSTRAINT display_field_data_23656_fk FOREIGN KEY
(locations_miles_log_id)

                      REFERENCES locations_miles_log

                      (locations_miles_log_id) MATCH SIMPLE ON UPDATE

                       NO ACTION ON DELETE CASCADE

                )]

Shortly (30m) after running that through Slonik, our application crashed
due to unreleased locks on tables. We checked, and the CREATE TABLE
statement generated by Slonik was still in progress, presumably waiting. We
had not yet added the created tables to replication; all we had done was
run slonik_execute_script. It is possible that this is coincidental, and a
problem with our application’s structure. However, that seems remote,
considering the thousands of similar such changes we have made in the past,
before we used Slony. Do you have any ideas why this might have occurred,
or of why passing table creation statements through SLONIK EXECUTE SCRIPT
might cause locking issues?
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