Reindexing: Maximizing PostgreSQL Performance

In my previous blog post, we delved into the impact of memory parameters on database performance. Now, let's shift our focus to another crucial aspect: reindexing in PostgreSQL and its profound influence on enhancing database performance.

Boosting Query Performance using Reindexing

Reindexing can work wonders for your query speed. Think of it as decluttering your database – optimizing indexes and trimming down the data it needs to sift through. If your indexes are looking a bit bloated with a fragmentation rate of over 40%, it’s definitely worth considering.

Detecting the need of Reindexing

How do you know when it’s time to reindex? Keep a close watch on that index bloat. Regular check-ins can help you spot when your database is due for a tune-up.

A quick checklist

Before you decide performing the REINDEX button, take moments to consider below :

• Is index bloat progressively worsening over time? If yes, it’s a clear signal for action.
• Is the bloat persistent but not escalating? A round of REINDEX might do the trick.

 |  schemaname  |        tablename        | est_rows  |  mb_bloat | table_mb
-+--------------+-------------------------+-----------+-----------+-----------
 | pg_bloat_tst | local_registry          |     34811 |     70.98 |    76.180
 | pg_bloat_tst | global_registry 	  |    170100 |    172.66 |   243.570
 | pg_bloat_tst | regional_registry       | 327709000 |  32130.32 | 84278.930
 | pg_bloat_tst | overall_registry        | 140051000 |   8647.16 | 29533.930
 | pg_bloat_tst | claim_registry          | 393537000 |  22570.70 | 81757.523

• Now, validate if application performance receive a boost post-REINDEX? If so, you’re on the right track.
• Is index bloat returning with a vengeance? If not, it might be best to leave it be.

Concurrent Rebuilding

Imagine you're fixing up your database, but every time you try to rebuild an index, it's like hitting pause on everything else.

PostgreSQL has a neat trick called concurrent rebuilding. Instead of putting a lock on your table and blocking every other operations out. It still does the work of rebuilding the index, but it does it in a way that lets other stuff keep happening at the same time.

With concurrent rebuilding, --

PostgreSQL takes a bit more time and does a bit more work. Because it has to scan the table twice for each index it's fixing and wait for other things to finish before it can start. But, it's worth it because it keeps your database running smoothly even while it's getting tidier. Doing things this way can slow down your database a bit, especially if it's already pretty busy. 

Final Thoughts

Next time you need to rebuild an index on the fly, remember: with PostgreSQL's concurrent rebuilding, you can keep things moving.

Reindexing isn’t just about fine-tuning the indexes – it’s about optimizing your database for peak performance. So, next time your queries are dragging their feet, give reindexing a shot. Your database – and your sanity – will thank you. 😉