Dictionary/Catalog view.
select * from pg_settings where category like ‘File%’
Dictionary/Catalog view.
select * from pg_settings where category like ‘File%’
select * from pg_stat_activity where datname = ‘<dn_name>’;
Sometimes it is necessary for the database administrator to remove existing connected sessions. For example to drop a database when users and/or applications cannot (or will not) disconnect or terminate cleanly.
SELECT pg_terminate_backend(pg_stat_activity.pid) FROM pg_stat_activity WHERE pg_stat_activity.datname = 'database_name_with_existing_sessions' AND pid <> pg_backend_pid();
Connect with the -E option psql -E ..... Then: postgres=# \du ********* QUERY ********** SELECT r.rolname, r.rolsuper, r.rolinherit, r.rolcreaterole, r.rolcreatedb, r.rolcanlogin, r.rolconnlimit, r.rolvaliduntil, ARRAY(SELECT b.rolname FROM pg_catalog.pg_auth_members m JOIN pg_catalog.pg_roles b ON (m.roleid = b.oid) WHERE m.member = r.oid) as memberof , r.rolreplication , r.rolbypassrls FROM pg_catalog.pg_roles r WHERE r.rolname !~ '^pg_' ORDER BY 1; ************************** List of roles Role name | Attributes | Member of ---------------------+------------------------------------------------------------+-----------
psql is the PostgreSQL interactive terminal. Usage: psql [OPTION]... [DBNAME [USERNAME]] General options: -c, --command=COMMAND run only single command (SQL or internal) and exit -d, --dbname=DBNAME database name to connect to (default: "RAYFOX") -f, --file=FILENAME execute commands from file, then exit -l, --list list available databases, then exit -v, --set=, --variable=NAME=VALUE set psql variable NAME to VALUE (e.g., -v ON_ERROR_STOP=1) -V, --version output version information, then exit -X, --no-psqlrc do not read startup file (~/.psqlrc) -1 ("one"), --single-transaction execute as a single transaction (if non-interactive) -?, --help[=options] show this help, then exit --help=commands list backslash commands, then exit --help=variables list special variables, then exit Input and output options: -a, --echo-all echo all input from script -b, --echo-errors echo failed commands -e, --echo-queries echo commands sent to server -E, --echo-hidden display queries that internal commands generate -L, --log-file=FILENAME send session log to file -n, --no-readline disable enhanced command line editing (readline) -o, --output=FILENAME send query results to file (or |pipe) -q, --quiet run quietly (no messages, only query output) -s, --single-step single-step mode (confirm each query) -S, --single-line single-line mode (end of line terminates SQL command) Output format options: -A, --no-align unaligned table output mode -F, --field-separator=STRING field separator for unaligned output (default: "|") -H, --html HTML table output mode -P, --pset=VAR[=ARG] set printing option VAR to ARG (see \pset command) -R, --record-separator=STRING record separator for unaligned output (default: newline) -t, --tuples-only print rows only -T, --table-attr=TEXT set HTML table tag attributes (e.g., width, border) -x, --expanded turn on expanded table output -z, --field-separator-zero set field separator for unaligned output to zero byte -0, --record-separator-zero set record separator for unaligned output to zero byte Connection options: -h, --host=HOSTNAME database server host or socket directory (default: "local socket") -p, --port=PORT database server port (default: "5432") -U, --username=USERNAME database user name (default: "RAYFOX") -w, --no-password never prompt for password -W, --password force password prompt (should happen automatically) For more information, type "\?" (for internal commands) or "\help" (for SQL commands) from within psql, or consult the psql section in the PostgreSQL documentation. Report bugs to <pgsql-bugs@postgresql.org>.