T_WEBUI_ViewSelection[Line] shall be truncated and not deleted

[teosarca]

Is this a bug or feature request?

bug

What is the current behavior?

on startup, those 2 tables are "DELETE FROM".

What is the expected or desired behavior?

we shall use TRUNCATE.

Shall be fixed in de.metas.ui.web.view.ViewsRepository.truncateTable(String)

[metas-ts]

Hi @teosarca @metasnw
truncating is is only a workaround..i guess it's OK since it's little effort now, but

• we can't assume to have a downtime in which the truncate could be performed, so we are back at delete..we need to identify old records and remove them, on a regular base.
  • e.g. if the session of the user for which the selection was made ends
• if we clean upon a regular basis, the table will stop growing at a certain point. It's true that disk space is not returned to the OS on the system, but given a proper vacuum setup (1. we need it anyways; 2. even with the default seup this holds true), the table's disk usage won't grow boundless, because disk space will be reused.

So if nothing else, i suggest to do a follow-up task to deal with this issue properly

[metasnw]

@teosarca @metas-ts
yes, we can do a follow up but we need the truncate asap to have a 80% solution at all

[metas-ts]

hi @metasnw @teosarca ,
@metas-mk just talked with me about this.
A solution is not the truncate, but regular restarts.
Anyways you need those restarts right now.
the only difference wrt the disk usage is that with truncate, you get a sawtooth pattern and with delete, a "flat line" which is aproximately at the sawtooth's maximum

[metas-mk]

@metas-ts decided for truncate in startup (as proposed in issue)

[metas-dh]

checked with ts: does not need testing, created follow-up #737