I just implemented eRServer for one of my clients and found many
problems with it.
- It
crashes when using “ers_addtable” to add big tables. The problem is that
it used pg_dump –d then tried to read the whole output in memory. I fixed
it by reading one row at a time and inserting it to slave.
- “ers_addslave”
crashes when creating table schema if one rows on the master were dropped.
Apparently, when a row was dropped, the “attname” in “pg_attribute” table
was changed to “………pg.dropped.#…………..” and the type of the column became “-“.
That made the “create table” sql statement for slave wrong. I fixed this
problem by excluding those kind of columns.
- There
was no index created on “_ers_uniq” on slave side. It took minutes per
transaction to delete on huge tables. After I found the problem and
created index on the column, it only took about 5 milliseconds to delete.
- To
handle columns with default and nextval, eRServer expected to see nextval('"sequence_name"'::text)
and used double quote to extract sequence names. But postgres also allow nextval('sequence_name'::text)
without double quotes. The fix was easy.
- eRServer.pm
failed because DBI could not handle columns with types such as “text[]”
but Pg module should work.
Hope those will be fixed in the next
version. I can also provide my fixes if needed.
John
Li
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