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In order to have the option to use O_DIRECT/FILE_FLAG_NO_BUFFERING in a
later commit, we need the addresses of user space buffers to be well
aligned. The exact requirements vary by OS and file system (typically
sectors and/or memory pages). The address alignment size is set to
4096, which is enough for currently known systems: it matches modern
sectors and common memory page size. There is no standard governing
O_DIRECT's requirements so we might eventually have to reconsider this
with more information from the field or future systems.
Aligning I/O buffers on memory pages is also known to improve regular
buffered I/O performance.
Three classes of I/O buffers for regular data pages are adjusted:
(1) Heap buffers are now allocated with the new palloc_aligned() or
MemoryContextAllocAligned() functions introduced by commit
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.. | ||
adminpack | ||
amcheck | ||
auth_delay | ||
auto_explain | ||
basebackup_to_shell | ||
basic_archive | ||
bloom | ||
bool_plperl | ||
btree_gin | ||
btree_gist | ||
citext | ||
cube | ||
dblink | ||
dict_int | ||
dict_xsyn | ||
earthdistance | ||
file_fdw | ||
fuzzystrmatch | ||
hstore | ||
hstore_plperl | ||
hstore_plpython | ||
intagg | ||
intarray | ||
isn | ||
jsonb_plperl | ||
jsonb_plpython | ||
lo | ||
ltree | ||
ltree_plpython | ||
oid2name | ||
old_snapshot | ||
pageinspect | ||
passwordcheck | ||
pg_buffercache | ||
pg_freespacemap | ||
pg_prewarm | ||
pg_stat_statements | ||
pg_surgery | ||
pg_trgm | ||
pg_visibility | ||
pg_walinspect | ||
pgcrypto | ||
pgrowlocks | ||
pgstattuple | ||
postgres_fdw | ||
seg | ||
sepgsql | ||
spi | ||
sslinfo | ||
start-scripts | ||
tablefunc | ||
tcn | ||
test_decoding | ||
tsm_system_rows | ||
tsm_system_time | ||
unaccent | ||
uuid-ossp | ||
vacuumlo | ||
xml2 | ||
contrib-global.mk | ||
Makefile | ||
meson.build | ||
README |
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.