mirror of
https://github.com/postgres/postgres.git
synced 2025-05-06 19:59:18 +03:00
37507962c3
connectby() didn't adequately check that the constructed SQL query returns what it's expected to; in fact, since commit 08c33c426bfebb32 it wasn't checking that at all. This could result in a null-pointer-dereference crash if the constructed query returns only one column instead of the expected two. Less excitingly, it could also result in surprising data conversion failures if the constructed query returned values that were not I/O-conversion-compatible with the types specified by the query calling connectby(). In all branches, insist that the query return at least two columns; this seems like a minimal sanity check that can't break any reasonable use-cases. In HEAD, insist that the constructed query return the types specified by the outer query, including checking for typmod incompatibility, which the code never did even before it got broken. This is to hide the fact that the implementation does a conversion to text and back; someday we might want to improve that. In back branches, leave that alone, since adding a type check in a minor release is more likely to break things than make people happy. Type inconsistencies will continue to work so long as the actual type and declared type are I/O representation compatible, and otherwise will fail the same way they used to. Also, in all branches, be on guard for NULL results from the constructed query, which formerly would cause null-pointer dereference crashes. We now print the row with the NULL but don't recurse down from it. In passing, get rid of the rather pointless idea that build_tuplestore_recursively() should return the same tuplestore that's passed to it. Michael Paquier, adjusted somewhat by me
The PostgreSQL contrib tree
---------------------------
This subtree contains porting tools, analysis utilities, and plug-in
features that are not part of the core PostgreSQL system, mainly
because they address a limited audience or are too experimental to be
part of the main source tree. This does not preclude their
usefulness.
User documentation for each module appears in the main SGML
documentation.
When building from the source distribution, these modules are not
built automatically, unless you build the "world" target. You can
also build and install them all by running "make all" and "make
install" in this directory; or to build and install just one selected
module, do the same in that module's subdirectory.
Some directories supply new user-defined functions, operators, or
types. To make use of one of these modules, after you have installed
the code you need to register the new SQL objects in the database
system by executing a CREATE EXTENSION command. In a fresh database,
you can simply do
CREATE EXTENSION module_name;
See the PostgreSQL documentation for more information about this
procedure.