Essentially the CTATopLevelDirsHelper table and its logic are removed
and the new logic is that eos-import-dirs will accept as argument
a top-level directory from which to run the injection.

Following discussions, it appears that experiments will be able
to only change a fixed prefix, i.e. /castor/cern.ch -> /eos/cta<instance>,
and not the deeper path components.
Moreover, we need to call getPathForFileId() on missing paths,
therefore an extra synonym + grant is added here.

- The CTADirsHelper is now a view as opposed to a table, and
a new CTATopLevelDirsHelper table has been created. Grants
have been changed accordingly.
- The CTA schema also got a new synonym to access the real table
underlying the CTADirsHelper view in order to speed up one query.

Turns out that properly splitting the query with a "persistent"
temp table is ~2x faster than the full query.

Giuseppe Lo Presti authored Jun 21, 2019 and Michael Davis committed Jun 24, 2019

CASTOR migration: alternate implementation to fill the directories intermediate table with no temp table

Giuseppe Lo Presti authored Jun 21, 2019 and Michael Davis committed Jun 24, 2019

This should solve "ORA-22813: operand value exceeds system limits"
errors happening when the exported files exceed 10M in one go.

CASTOR migration: alternate implementation to fill the directories intermediate table with no temp table

This should solve "ORA-22813: operand value exceeds system limits"
errors happening when the exported files exceed 10M in one go.

The code now runs in parallel mode according to Oracle EM.

The full path is only stored in the CTADirsHelper table, whereas the
CTAFilesHelper table contains only the filename along with all other
relevant metadata fields.

Among others:
- need to create Logical_library entities if missing
- tapes in VMGR are marked as EXPORTED via PL/SQL

Implemented latest decisions as documented in #488. The PL/SQL code is ready for testing once the schema changes are available.

Moreover, the PL/SQL code for the CTA catalogue is temporarily
moved out of the catalogue folder as it requires some schema
changes that are still work in progress in a dev branch. Until
then, all migration code is evolved in the migration/ folder.

References:
https://gitlab.cern.ch/cta/CTA/issues/479 (on the CTA side)
Jira: CASTOR-5526: support the migration to CTA (on the CASTOR side)

The latter won't be updated further, all required code will
be committed here and gitlab tickets will be updated accordingly.