Use builtin array_remove() function rather than our custom version

[Mike Rylander]

As of Postgres 9.3 there is a built in array_remove() function that is faster than our custom version that uses unnest(). We should use that instead. Branch forthcoming...

[Mike Rylander (mrylander)]

Branch at:

http://git.evergreen-ils.org/?p=working/Evergreen.git;a=shortlog;h=refs/heads/user/miker/lp-1778955-use-builtin-array_remove

[Dan Pearl (dpearl)]

This code is difficult to check by only its behavior (which should be identical to the old behavior), but while doing a desk check, I saw something unusual.

In The code that previously defined the evergreen.array_remove_item_by_value function, the name of the function has been changed to the built-in (perhaps the result of a global replace?). So the code now looks like

CREATE OR REPLACE FUNCTION array_remove(inp ANYARRAY, el ANYELEMENT)
 RETURNS anyarray AS $$
     SELECT ARRAY_AGG(x.e) FROM UNNEST( $1 ) x(e) WHERE x.e <> $2;

I'm not sure what Postgres does when you redefine a built-in, but my guess is that this code
should be removed. It certainly looks out of place.

[Jane Sandberg (sandbergja)]

Thanks for this branch, Mike, and for catching that issue, Dan. I signed off at user/sandbergja/lp-1778955-use-builtin-array_remove

That branch also includes a commit to remove the issue that Dan found (it's a little odd that we were defining our custom function twice), as well as a little copy pasta that found its way into the upgrade script.

I also opted to uncomment the last line of your upgrade script, Mike, so that upgraded Evergreens aren't left with our custom function, in the hopes that removing it might reduce some confusion down the line.

It would be great to get this merged sooner rather than later, so nobody starts building new code off the old versions of these functions!

[Rogan Hamby (rogan-hamby)]

I thought I had tested and signed off on this so I will do so today (assuming testing goes well).

[Rogan Hamby (rogan-hamby)]

sign off pushed to user/rogan/lp1778955_use_native_array_remove

[Galen Charlton (gmc)]

Pushed down to rel_3_6. Thanks, Mike, Dan, Jane, and Rogan!