We have a lot of code in which option names, which from the user's
viewpoint are logically keywords, are passed through the grammar as plain
identifiers, and then matched to string literals during command execution.
This approach avoids making words into lexer keywords unnecessarily. Some
places matched these strings using plain strcmp, some using pg_strcasecmp.
But the latter should be unnecessary since identifiers would have been
downcased on their way through the parser. Aside from any efficiency
concerns (probably not a big factor), the lack of consistency in this area
creates a hazard of subtle bugs due to different places coming to different
conclusions about whether two option names are the same or different.
Hence, standardize on using strcmp() to match any option names that are
expected to have been fed through the parser.
This does create a user-visible behavioral change, which is that while
formerly all of these would work:
alter table foo set (fillfactor = 50);
alter table foo set (FillFactor = 50);
alter table foo set ("fillfactor" = 50);
alter table foo set ("FillFactor" = 50);
now the last case will fail because that double-quoted identifier is
different from the others. However, none of our documentation says that
you can use a quoted identifier in such contexts at all, and we should
discourage doing so since it would break if we ever decide to parse such
constructs as true lexer keywords rather than poor man's substitutes.
So this shouldn't create a significant compatibility issue for users.
Daniel Gustafsson, reviewed by Michael Paquier, small changes by me
Discussion: https://postgr.es/m/29405B24-564E-476B-98C0-677A29805B84@yesql.se
SQL has standardized on => as the use of to specify named parameters,
and we've wanted for many years to support the same syntax ourselves,
but this has been complicated by the possible use of => as an operator
name. In PostgreSQL 9.0, we began emitting a warning when an operator
named => was defined, and in PostgreSQL 9.2, we stopped shipping a
=>(text, text) operator as part of hstore. By the time the next major
version of PostgreSQL is released, => will have been deprecated for a
full five years, so hopefully there won't be too many people still
relying on it. We continue to support := for compatibility with
previous PostgreSQL releases.
Pavel Stehule, reviewed by Petr Jelinek, with a few documentation
tweaks by me.
to note:
1) arttype is numeric. I thought this was the best way of allowing
arbitarily large factorials, even though factorial(2^63) is a large
number. Happy to change to integers if this is overkill.
2) since we're accepting numeric arguments, the patch tests for floats.
If a numeric is passed with non-zero decimal portion, an error is raised
since (from memory) they are undefined.
Gavin Sherry
large objects. Dump all these in pg_dump; also add code to pg_dump
user-defined conversions. Make psql's large object code rely on
the backend for inserting/deleting LOB comments, instead of trying to
hack pg_description directly. Documentation and regression tests added.
Christopher Kings-Lynne, code reviewed by Tom
OK, here are a passel of patches for the geometric data types.
These add a "circle" data type, new operators and functions
for the existing data types, and change the default formats
for some of the existing types to make them consistant with
each other. Current formatting conventions (e.g. compatible
with v6.0 to allow dump/reload) are supported, but the new
conventions should be an improvement and we can eventually
drop the old conventions entirely.
For example, there are two kinds of paths (connected line segments),
open and closed, and the old format was
'(1,2,1,2,3,4)' for a closed path with two points (1,2) and (3,4)
'(0,2,1,2,3,4)' for an open path with two points (1,2) and (3,4)
Pretty arcane, huh? The new format for paths is
'((1,2),(3,4))' for a closed path with two points (1,2) and (3,4)
'[(1,2),(3,4)]' for an open path with two points (1,2) and (3,4)
For polygons, the old convention is
'(0,4,2,0,4,3)' for a triangle with points at (0,0),(4,4), and (2,3)
and the new convention is
'((0,0),(4,4),(2,3))' for a triangle with points at (0,0),(4,4), and (2,3)
Other data types which are also represented as lists of points
(e.g. boxes, line segments, and polygons) have similar representations
(they surround each point with parens).
For v6.1, any format which can be interpreted as the old style format
is decoded as such; we can remove that backwards compatibility but ugly
convention for v7.0. This will allow dump/reloads from v6.0.
These include some updates to the regression test files to change the test
for creating a data type from "circle" to "widget" to keep the test from
trashing the new builtin circle type.
