Gbase 8C general file access function

The general file access function provides a local access interface to the files on the database server . Only GBase 8c Contents and log_directory The files in the directory can be accessed . Use relative paths to access GBase 8c Files in the directory , And matching log_directory Configure the path set to access the log file . Only database initialization users can use these functions .

pg_ls_dir(dirname text)

describe ： List the files in the directory .

return type ：setof text

remarks ：pg_ls_dir Return the special items in the specified directory “.” and “..” All names except .

Example ：

gbase=# SELECT pg_ls_dir('./');

      pg_ls_dir

----------------------

 global

 pg_xlog

 pg_clog

 pg_csnlog

 pg_notify

 pg_serial

 pg_snapshots

 pg_twophase

 pg_multixact

 base

 pg_replslot

 pg_tblspc

 pg_stat_tmp

 pg_llog

 pg_errorinfo

 undo

 pg_logical

 pg_location

 PG_VERSION

 pg_ctl.lock

 postgresql.conf.lock

 postmaster.pid.lock

 mot.conf

 gs_gazelle.conf

 pg_hba.conf

 pg_ident.conf

 postgresql.conf.bak

 server.crt

 server.key

 cacert.pem

 server.key.cipher

 server.key.rand

 pg_hba.conf.lock

 pg_hba.conf.bak

 gaussdb.state

 postmaster.opts

 gswlm_userinfo.cfg

 postgresql.conf

 postmaster.pid

(39 rows)

pg_read_file(filename text, offset bigint, length bigint)

describe ： Return the contents of a text file .

return type ：text

remarks ：pg_read_file Returns part of a text file , from offset Start , Back at most length byte （ If you reach the end of the file first , Is less than this value ）. If offset It's a negative number , Then it is the length of the fallback relative to the end of the file . If you omit offset and length, Then the entire file is returned .

Example ：

 gbase=# SELECT pg_read_file('postmaster.pid',0,100);

               pg_read_file

-------------------------------------------

 7961                                     +

 /home/gbase/project/install/data/dn/dn1_1+

 1651723153                               +

 20008                                    +

 /home/gbase/gbase8c/tmp                  +

 [local_ip]                               +

  2

(1 row)