Update database layout version number to 1.2 consequently This new capability will be used by IAU planetary CRS (refs #2601)
None of our tables are indexed by a INTEGER PRIMARY KEY, but most of them are by a (auth_name, code) primary key. Consequently they can benefit from being created as WITHOUT ROWID tables (https://sqlite.org/withoutrowid.html), which avoids an index to be created on the rowid we don't use. WITHOUT ROWID is a feature added in SQLite 3.8.2, so as our baseline is 3.11, we can use it. This decreases the DB size from 7,749,632 to 7,229,440 bytes, without any measurable consequence on performance.
Non-trivial updates: - some vertical CRS are now encoded as DerivedVerticalCRS. e.g EPSG:8228 "NAVD88 height (ft)", with base EPSG:5703 "NAVD88 height". As we don't have support in our PROJ db model for DerivedVerticalCRS, modify the import script to 'resolve' the derivation up to the original datum. - Method EPSG:1069 'Change of Vertical Unit' is no longer used. It is replaced by a generic-purpose EPSG:1104 method that doesn't take any conversion factor. And generic conversions EPSG:7812 and EPSG:7813 are now used in concatenated operations, which require code changes as well.
We never select by those columns, so don't set them. Reduce from 8.4 to 7.9 MB. Upgrade the minor version of the database layout. (that database can still be read by PROJ 8.0)
Most codes (especially *all* in EPSG) are integers. As integers are stored as variable-length in the db, it is preferable to store them as such when possible. So use a special INTEGER_OR_TEXT data type. This is a "non-standard" type declaration, but this is perfectly legal as SQLite is loosely typed. As this declaration contains the string INT, it is assigned INTEGER affinity. Which means that values provided either as text (that contains integer value) or integer will be stored as integers, whereas text values will be stored as text. See paragraph 3 and 3.1 of https://www.sqlite.org/datatype3.html. The "INTEGER_OR_TEXT" name is a hint for the user, and software like GDAL (>= 3.3) to expose the column as string... The effect of using this rather than TEXT is making the DB size go from 9 MB to 8.4. There is no need to change the DATABASE.LAYOUT version numbering as this is completely forward and backward compatible.