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Introduction

CAST Storage Service (CSS) 3 is a re-packaged PostgreSQL 9.6.11, while CAST Storage Service 4 uses PostgreSQL 13. Since the EOL for PostgreSQL 9.6.x is scheduled for November 2021, CAST would encourage you to upgrade your instance wherever possible. Over and above the benefits of using a PostgreSQL release that is not due to go EOL until November 2025, the improvements added to PostgreSQL between 9.6 and 13 are worth highlighting - these improvements also provide better performance for use with CAST AIP.

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The built in VACUUM process is much faster on CSS4/PostgreSQL 13 because of the ability to vacuum indexes in parallel which was not supported in CSS3 in CSS3/PostgreSQL 9.6.x (you can run a VACUUM process directly in AIP Console - see Administration Center - Settings - CSS Optimization). If you are running VACUUM manually using PgAdmin or an equivalent tool, you can also specify the PARALLEL directive to control how many parallel VACUUM jobs you want running on your indexes - see https://www.postgresql.org/docs/current/sql-vacuum.html.

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Limit  (cost=7.52..100.14 rows=13 width=8) (actual time=0.135..0.140 rows=13 loops=1)
  ->  Incremental Sort  (cost=7.52..35633.43 rows=5000 width=8) (actual time=0.133..0.136 rows=13 loops=1)
        Sort Key: x, y DESC
        Presorted Key: x
        Full-sort Groups: 1  Sort Method: quicksort  Average Memory: 25kB  Peak Memory: 25kB
        ->  Index Scan using abc_pkey on abc  (cost=0.42..35408.43 rows=5000 width=8) (actual time=0.044..0.113 rows=14 loops=1)
              Filter: ((x % 13) = 0)
              Rows Removed by Filter: 168
Planning Time: 0.617 ms
Execution Time: 0.177 ms

Overall

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analysis/snapshot execution time improvements

Running the same upgrade process and the same analysis/snapshot on the same host server using CSS3 and CSS4 shows a clear an improvement in performance for CSS4:

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