future proof build-db.sh

[Ben Shum]

Evergreen master

In Open-ILS/src/sql/Pg/build-db.sh, we have this line to grab and select the database version:

DB_VERSION=`psql -qtc 'show server_version;' | xargs | cut -c1,3`

In most cases, this results in the first and third character being pulled into the version, like:

version = 9.5.9 becoming "95" as the result.

With the upcoming PostgreSQL 10, this comes back as:

version = 10.0 becoming "1." as the result.

Grabbing an idea from the comparison recently added in eg_db_config to test for higher postgresql versions, we should change the line to be like this:

DB_VERSION=`psql -qtc 'show server_version;' | xargs | cut -d. -f 1,2 | tr -d '.'`

This properly results in a DB_VERSION value like "100" with PostgreSQL 10.0

Patch forthcoming to future proof and fix build-db.sh script.

[Ben Shum (bshum)]

Working branch: user/bshum/lp1730721-fix-build-db.sh

http://git.evergreen-ils.org/?p=working/Evergreen.git;a=shortlog;h=refs/heads/user/bshum/lp1730721-fix-build-db.sh

[Jason Stephenson (jstephenson)]

Works for me and a good catch!

Pushed to master for future use.

[Mike Rylander (mrylander)]

Please note, from version 10 on, Postgres will be changing the way versions are numbered. The result is that we will only want to track the first component from here on out, rather than the first and second. Since there won't be a two digit component of the first two from <= 9.6, we can instead just start taking the first two numeric characters in the version string. Granted, we'll have to revisit when PG hits version 100, in about 90 years, but hopefully we'll all individually have figured out something better to do by then, with our flying cars and our moon bases.

[Ben Shum (bshum)]

Hmm, Mike's right, the versioning change for PostgreSQL 10+ will change how this behaves.

Follow patch on tip of same working branch.

[Jason Stephenson (jstephenson)]

Mike is definitely correct, I signed off and pushed the correction to use just the first two characters from the db version so that we have fewer create database scripts going forward.