Inefficiency of Empty JSONB Objects

[jonas-jasas]

Migrated to mobility 1.3.1 and had to change all JSONB NULL values to {} (related issue #666). NULL takes no space, while {} takes ~20b. I have the table with the many records and just few contains JSONB field values. As the result of changing NULL to {} database doubled in size from 40Gb to 80Gb.

Any suggestions how to solve this database size issue?

[jonas-jasas]

For everyone who goes through this operation:
Converting from NULL to {} unexpectedly reserves crazy amounts of disk space. Just by running VACUUM (FULL); reclaims all that space. Vacuum operation executes surprisingly fast, not sure if it is related to this particular operation or to PG v17. In my case database deflated from 80Gb to 40Gb in just 20min on a slow VM.