Discussed in #1203

Phase 1 (scheduled for 24.1.1):

• After a record delete, the page should be compressed by shifting the records to the left making space for new records
• Delete records should have pointers = 0 and not valid pointers with zero length buffers. This would save precious bytes and would make the page 100% reusable
• Update the total record in the page counter when the last record is deleted: cycle left the pointers while the pointers are 0. Then update the total records on the page
• Consider calling compressPage() at commit time only if a page has been updated or deleted (insert does not create holes)
• More random stress tests with heavy multi-threads load to check for bugs on reclaimed space (Unknown issue with using unique index + loading multi-page records under heavy load #1402)

Phase 2 (it will be separated into a new issue):

• When an insert/update needs a new page, scan the previous pages to find a hole to reuse. This allows to execute this scan only at new pages, so in the best case 1 time every 2048 inserted records
• Consider saving holes on a different structure to be quickly reused without a scan
• To properly recover the space occupied by shrunk multi-page records (a record spans over multiple pages and then shrinks in size)
• Deleted empty segments in edge linked list