The stanza in ECPGconnect() that intended to allow specification of a
Unix socket directory path in place of a port has never executed since
it was committed, nearly two decades ago; the preceding strrchr()
already found the last colon so there cannot be another one. The lack
of complaints about that is doubtless related to the fact that no
user-facing documentation suggested it was possible.
Rather than try to fix that up, let's just remove the unreachable
code, and instead document the way that does work to write a socket
directory path, namely specifying it as a "host" option.
In support of that, make another pass at clarifying the syntax
documentation for ECPG connection targets, particularly documenting
which things are parsed as identifiers and where to use double quotes.
Rearrange some things that seemed poorly ordered, and fix a couple of
minor doc errors.
Kyotaro Horiguchi, per gripe from Shenhao Wang
(docs changes mostly by me)
Discussion: https://postgr.es/m/ae52a416bbbf459c96bab30b3038e06c@G08CNEXMBPEKD06.g08.fujitsu.local
ECPG's PREPARE ... FROM and EXECUTE IMMEDIATE can optionally take
the target query as a simple literal, rather than the more usual
string-variable reference. This was previously documented as
being a C string literal, but that's a lie in one critical respect:
you can't write a data double quote as \" in such literals. That's
because the lexer is in SQL mode at this point, so it'll parse
double-quoted strings as SQL identifiers, within which backslash
is not special, so \" ends the literal.
I looked into making this work as documented, but getting the lexer
to switch behaviors at just the right point is somewhere between
very difficult and impossible. It's not really worth the trouble,
because these cases are next to useless: if you have a fixed SQL
statement to execute or prepare, you might as well write it as
a direct EXEC SQL, saving the messiness of converting it into
a string literal and gaining the opportunity for compile-time
SQL syntax checking.
Instead, let's just document (and test) the workaround of writing
a double quote as an octal escape (\042) in such cases.
There's no code behavioral change here, so in principle this could
be back-patched, but it's such a niche case I doubt it's worth
the trouble.
Per report from 1250kv.
Discussion: https://postgr.es/m/673825.1603223178@sss.pgh.pa.us
If you write the literal 'abc''def' in an EXEC SQL command, that will
come out the other end as 'abc'def', triggering a syntax error in the
backend. Likewise, "abc""def" is reduced to "abc"def" which is wrong
syntax for a quoted identifier.
The cause is that the lexer thinks it should emit just one quote
mark, whereas what it really should do is keep the string as-is.
Add some docs and test cases, too.
Although this seems clearly a bug, I fear users wouldn't appreciate
changing it in minor releases. Some may well be working around it
by applying an extra doubling of affected quotes, as for example
sql/dyntest.pgc has been doing.
Per investigation of a report from 1250kv, although this isn't
exactly what he/she was on about.
Discussion: https://postgr.es/m/673825.1603223178@sss.pgh.pa.us
SQL commands are generally marked up as <command>, except when a link
to a reference page is used using <xref>. But the latter doesn't
create monospace markup, so this looks strange especially when a
paragraph contains a mix of links and non-links.
We considered putting <command> in the <refentrytitle> on the target
side, but that creates some formatting side effects elsewhere.
Generally, it seems safer to solve this on the link source side.
We can't put the <xref> inside the <command>; the DTD doesn't allow
this. DocBook 5 would allow the <command> to have the linkend
attribute itself, but we are not there yet.
So to solve this for now, convert the <xref>s to <link> plus
<command>. This gives the correct look and also gives some more
flexibility what we can put into the link text (e.g., subcommands or
other clauses). In the future, these could then be converted to
DocBook 5 style.
I haven't converted absolutely all xrefs to SQL command reference
pages, only those where we care about the appearance of the link text
or where it was otherwise appropriate to make the appearance match a
bit better. Also in some cases, the links where repetitive, so in
those cases the links where just removed and replaced by a plain
<command>. In cases where we just want the link and don't
specifically care about the generated link text (typically phrased
"for further information see <xref ...>") the xref is kept.
Reported-by: Dagfinn Ilmari Mannsåker <ilmari@ilmari.org>
Discussion: https://www.postgresql.org/message-id/flat/87o8pco34z.fsf@wibble.ilmari.org
This ought to work much like C's "#elif defined(name)"; but the code
implemented it in a way equivalent to endif followed by ifdef, so that
it didn't matter whether any previous branch of the IF construct had
succeeded. Fix that; add some test cases covering elif and nested IFs;
and improve the documentation, which also seemed a bit confused.
AFAICS the code has been like this since the feature was added in 1999
(commit b57b0e044). So while it's surely wrong, there might be code
out there relying on the current behavior. Hence, don't back-patch
into stable branches. It seems all right to fix it in v13 though.
Per report from Ashutosh Sharma. Reviewed by Ashutosh Sharma and
Michael Meskes.
Discussion: https://postgr.es/m/CAE9k0P=dQk9X0cU2tN49S7a9tv733-e1pVdpB1P-pWJ5PdTktg@mail.gmail.com
This reverts commit bd7c95f0c1,
along with assorted follow-on fixes. There are some questions
about the definition and implementation of that statement, and
we don't have time to resolve them before v13 release. Rather
than ship the feature and then have backwards-compatibility
concerns constraining any redesign, let's remove it for now
and try again later.
Discussion: https://postgr.es/m/TY2PR01MB2443EC8286995378AEB7D9F8F5B10@TY2PR01MB2443.jpnprd01.prod.outlook.com
Turn most mentions of libpq functions into links. At id attributes to
most libpq functions, where not existing yet, so that they can be
linked to. (In a handful of cases there were problems with the PDF
processing toolchain, so those instances were not changed.)
Author: Fabien COELHO <coelho@cri.ensmp.fr>
Reviewed-by: Peter Eisentraut <peter.eisentraut@2ndquadrant.com>
Discussion: https://www.postgresql.org/message-id/flat/alpine.DEB.2.21.1905121032330.27203@lancre
So far ECPG programs had to treat binary data for bytea column as 'char' type.
But this meant converting from/to escaped format with PQunescapeBytea/
PQescapeBytea() and therefore forcing users to add unnecessary code and cost
for the conversion in runtime. By adding a dedicated datatype for bytea most of
this special handling is no longer needed.
Author: Matsumura-san ("Matsumura, Ryo" <matsumura.ryo@jp.fujitsu.com>)
Discussion: https://postgr.es/m/flat/03040DFF97E6E54E88D3BFEE5F5480F737A141F9@G01JPEXMBYT04
DECLARE STATEMENT is a statement that lets users declare an identifier
pointing at a connection. This identifier will be used in other embedded
dynamic SQL statement such as PREPARE, EXECUTE, DECLARE CURSOR and so on.
When connecting to a non-default connection, the AT clause can be used in
a DECLARE STATEMENT once and is no longer needed in every dynamic SQL
statement. This makes ECPG applications easier and more efficient. Moreover,
writing code without designating connection explicitly improves portability.
Authors: Ideriha-san ("Ideriha, Takeshi" <ideriha.takeshi@jp.fujitsu.com>)
Kuroda-san ("Kuroda, Hayato" <kuroda.hayato@jp.fujitsu.com>)
Discussion: https://postgr.es/m4E72940DA2BF16479384A86D54D0988A565669DF@G01JPEXMBKW04
On Windows, it is sometimes important for corresponding malloc() and
free() calls to be made from the same DLL, since some build options can
result in multiple allocators being active at the same time. For that
reason we already provided PQfreemem(). This commit adds a similar
function for freeing string results allocated by the pgtypes library.
Author: Takayuki Tsunakawa
Reviewed-by: Kyotaro Horiguchi
Discussion: https://postgr.es/m/0A3221C70F24FB45833433255569204D1F8AD5D6%40G01JPEXMBYT05
The "l" (ell) width spec means something in the corresponding scanf usage,
but not here. While modern POSIX says that applying "l" to "f" and other
floating format specs is a no-op, SUSv2 says it's undefined. Buildfarm
experience says that some old compilers emit warnings about it, and at
least one old stdio implementation (mingw's "ANSI" option) actually
produces wrong answers and/or crashes.
Discussion: https://postgr.es/m/21670.1526769114@sss.pgh.pa.us
Discussion: https://postgr.es/m/c085e1da-0d64-1c15-242d-c921f32e0d5c@dunslane.net
The ability to create like-named objects in different schemas opens up
the potential for users to change the behavior of other users' queries,
maliciously or accidentally. When you connect to a PostgreSQL server,
you should remove from your search_path any schema for which a user
other than yourself or superusers holds the CREATE privilege. If you do
not, other users holding CREATE privilege can redefine the behavior of
your commands, causing them to perform arbitrary SQL statements under
your identity. "SET search_path = ..." and "SELECT
pg_catalog.set_config(...)" are not vulnerable to such hijacking, so one
can use either as the first command of a session. As special
exceptions, the following client applications behave as documented
regardless of search_path settings and schema privileges: clusterdb
createdb createlang createuser dropdb droplang dropuser ecpg (not
programs it generates) initdb oid2name pg_archivecleanup pg_basebackup
pg_config pg_controldata pg_ctl pg_dump pg_dumpall pg_isready
pg_receivewal pg_recvlogical pg_resetwal pg_restore pg_rewind pg_standby
pg_test_fsync pg_test_timing pg_upgrade pg_waldump reindexdb vacuumdb
vacuumlo. Not included are core client programs that run user-specified
SQL commands, namely psql and pgbench. PostgreSQL encourages non-core
client applications to do likewise.
Document this in the context of libpq connections, psql connections,
dblink connections, ECPG connections, extension packaging, and schema
usage patterns. The principal defense for applications is "SELECT
pg_catalog.set_config('search_path', '', false)", and the principal
defense for databases is "REVOKE CREATE ON SCHEMA public FROM PUBLIC".
Either one is sufficient to prevent attack. After a REVOKE, consider
auditing the public schema for objects named like pg_catalog objects.
Authors of SECURITY DEFINER functions use some of the same defenses, and
the CREATE FUNCTION reference page already covered them thoroughly.
This is a good opportunity to audit SECURITY DEFINER functions for
robust security practice.
Back-patch to 9.3 (all supported versions).
Reviewed by Michael Paquier and Jonathan S. Katz. Reported by Arseniy
Sharoglazov.
Security: CVE-2018-1058
This adds a new object type "procedure" that is similar to a function
but does not have a return type and is invoked by the new CALL statement
instead of SELECT or similar. This implementation is aligned with the
SQL standard and compatible with or similar to other SQL implementations.
This commit adds new commands CALL, CREATE/ALTER/DROP PROCEDURE, as well
as ALTER/DROP ROUTINE that can refer to either a function or a
procedure (or an aggregate function, as an extension to SQL). There is
also support for procedures in various utility commands such as COMMENT
and GRANT, as well as support in pg_dump and psql. Support for defining
procedures is available in all the languages supplied by the core
distribution.
While this commit is mainly syntax sugar around existing functionality,
future features will rely on having procedures as a separate object
type.
Reviewed-by: Andrew Dunstan <andrew.dunstan@2ndquadrant.com>
Since some preparation work had already been done, the only source
changes left were changing empty-element tags like <xref linkend="foo">
to <xref linkend="foo"/>, and changing the DOCTYPE.
The source files are still named *.sgml, but they are actually XML files
now. Renaming could be considered later.
In the build system, the intermediate step to convert from SGML to XML
is removed. Everything is build straight from the source files again.
The OpenSP (or the old SP) package is no longer needed.
The documentation toolchain instructions are updated and are much
simpler now.
Peter Eisentraut, Alexander Lakhin, Jürgen Purtz
IDs in SGML are case insensitive, and we have accumulated a mix of upper
and lower case IDs, including different variants of the same ID. In
XML, these will be case sensitive, so we need to fix up those
differences. Going to all lower case seems most straightforward, and
the current build process already makes all anchors and lower case
anyway during the SGML->XML conversion, so this doesn't create any
difference in the output right now. A future XML-only build process
would, however, maintain any mixed case ID spellings in the output, so
that is another reason to clean this up beforehand.
Author: Alexander Lakhin <exclusion@gmail.com>
For DocBook XML compatibility, don't use SGML empty tags (</>) anymore,
replace by the full tag name. Add a warning option to catch future
occurrences.
Alexander Lakhin, Jürgen Purtz
For XML compatibility, replace marked sections <![IGNORE[ ]]> with
comments <!-- -->. In some cases it seemed better to remove the ignored
text altogether, and in one case the text should not have been ignored.
When ecpg was rewritten to the new protocol version not all variable types
were corrected. This patch rewrites the code for these types to fix that. It
also fixes the documentation to correctly tell the status of array handling.
Long ago we briefly had an "autocommit" GUC that turned server-side
autocommit on and off. That behavior was removed in 7.4 after concluding
that it broke far too much client-side logic, and making clients cope with
both behaviors was impractical. But the GUC variable was left behind, so
as not to break any client code that might be trying to read its value.
Enough time has now passed that we should remove the GUC completely.
Whatever vestigial backwards-compatibility benefit it had is outweighed by
the risk of confusion for newbies who assume it ought to do something,
as per a recent complaint from Wolfgang Wilhelm.
In passing, adjust what seemed to me a rather confusing documentation
reference to libpq's autocommit behavior. libpq as such knows nothing
about autocommit, so psql is probably what was meant.