[QGIS-Developer] QGIS Oracle performance

[Tomas Straupis]

2019-11-30, št, 20:23 Alessandro Pasotti rašė:
> I don't know much about Oracle provider but I would say yes, there is also
> a setting named useEstimatedMetadata that should be used to tell the provider
> if we want to skip the deep and costly analysis and scans, at least in postgres
> this works well, not sure about Oracle.

  Use estimated metadata option was switched ON in my tests.
  In Oracle provider this means that say extent is queried in meta
information views rather than being calculated from actual data.
  This option does not skip re-checking of layer metadata (at least in
Oracle provider).
  In Oracle there is no way (known to me) to save geometry type in
meta information views and querying geometry type using actual large
query (via view) without any filter is in my test very slow and not
actually required as geometry type is selected when selecting
table/view in "Add vector source" dialog.

-- 
Tomas