OpenEdge Data Management: DataServer for Microsoft SQL Server

Prime to ROWID identification
inaccessible to DataServers). It also makes the designated primary and/or
clustered index now eligible for ROWID candidacy during migration.
Note: When the RECID field is used in this way, it is named
PROGRESS_RECID_UNIQUE, and not _PROGRESS_RECID. The name
change allows it to be utilized by the trigger and/or computed column,
and be populated on CREATE, but the name uniqueness prevents it
from being identified as a ROWID candidate by itself from the
dictionary utilities.
• Select ‘Best’ ROWID INDEX
Unselected by default, this option is mutually exclusive with the Create RECID
Field For options. If the Create RECID Field For options are unselected, this
option becomes mandatory.
When selected and used in conjunction with Migrate Constraints and/or Try
Primary for ROWID, it becomes a secondary path in the search for the
designated ROWID index. The primary and clustered selections associated with
those options will take priority in ROWID selection.
Note: This is a schema “pull” option, not a database “push” option and is therefore
unaffected by the Create RECID Field - For ROWID Uniqueness when
that option is selected.
– Using OE Schema (default) — Locate an existing index to use as ROWID,
if it qualifies, according to the requirements of the OE Schema. The criteria
of the OE Schema is described in the “Best index selection” section on
page 263. If a Best index selection can be found in the OE Schema, it is
designated as ROWID. Selecting this option provides backward compatibility
with earlier releases when those legacy migrations had the Create RECID
Field unselected.
– Using Foreign schema — Locate an existing index to use as ROWID from
the ODBC API that evaluates best index on the server. If a Best Index
selection can be found through the ODBC API, it is designated as ROWID.
Best index selection
The best index algorithm is used in the pull criteria when a primary index has not been
found to support ROWID through both dictionary and DataServer methodologies that
examine indexes in search of the optimal ROWID. The best index selection algorithm
takes place during schema pull after all the server objects are created. Prior to
Progress Version 7.3, a unique index with a single mandatory integer column was
required to set RECID/ROWID. From Version 7.3 until OpenEdge Release 11.0, a
single column index may be selected automatically if one or many columns exist that
meet the criteria of being mandatory and unique.
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