| From: | Robert Haas <robertmhaas(at)gmail(dot)com> |
|---|---|
| To: | Joel Jacobson <joel(at)trustly(dot)com> |
| Cc: | Craig Ringer <craig(at)2ndquadrant(dot)com>, Pg Hackers <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Re: SET NOT NULL [NOT VALID / CONCURRENTLY]? |
| Date: | 2016-12-22 16:16:32 |
| Message-ID: | CA+TgmoY9jpTW-Xi3GuL6G9-GiaTgR7FASutQd-fnRqwQTx+_xw@mail.gmail.com |
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| Lists: | pgsql-hackers |
On Wed, Dec 21, 2016 at 7:55 PM, Joel Jacobson <joel(at)trustly(dot)com> wrote:
> Attached is the function SET_NOT_NULL(_Schema name, _Table name, _Column
> name) which does the following:
>
> 1. LOCK TABLE %I.%I IN ACCESS EXCLUSIVE MODE
> just like the normal DDL commands would do
>
> 2. SELECT EXISTS (SELECT 1 FROM %I.%I WHERE %I IS NULL)
> which is fast if there is an index on the column
>
> 3. UPDATE pg_catalog.pg_attribute SET attnotnull = TRUE
> WHERE attrelid = %L::oid
> AND attname = %L
>
> Pragmatically, would this be a safe approach?
>
Hmm, I don't see a problem with it.
--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company
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