# Postgres
# PostgreSQL on macOS
## Install PostgreSQL using brew
```bash
brew install postgresql
```
List services maintained by brew
```bash
$ brew services list
Name Status User Plist
postgresql started lr ...
```
If you don't want it running as service you can manually start it with
```bash
postgres -D /usr/local/var/postgres
```
# Backslash commands
| | command |
|---|
| Toggle expanded display | `\x` |
| Toggle tuples only | `\t` |
| Connect to database | `\c db_name` |
| List databases | `\l` |
| Display table definition | `\d table_name` |
| Display triggers | `\dft` |
# Cheatsheet
### Truncate/empty all tables
```sql
SELECT 'TRUNCATE TABLE ' || tablename || ' CASCADE;' FROM pg_tables WHERE tableowner='acovix_devl';
```
### Show process / query list
```sql
SELECT * FROM pg_stat_activity;
-- active queries
SELECT pid, age(query_start, clock_timestamp()), usename, query
FROM pg_stat_activity
WHERE query != '' AND query NOT ILIKE '%pg_stat_activity%'
ORDER BY query_start desc;
```
### Kill running query
```sql
SELECT pg_cancel_backend(procpid);
-- kill idle query
SELECT pg_terminate_backend(procpid);
```
### List databases size
```sql
select datname, pg_size_pretty(pg_database_size(datname)) from pg_database order by pg_database_size(datname) desc;
```
### Show all triggers from a schema
```sql
SELECT
event_object_table,
trigger_name,
event_manipulation,
action_statement,
action_timing
FROM information_schema.triggers ORDER BY event_object_table, event_manipulation;
```
### Rename database
```sql
alter database old_name rename to new_name;
```
### Set database owner
```sql
alter database sample_name owner to david;
```
### Rename role
```sql
alter role role_name rename to new_role_name;
```
- set password, because after rename password is cleared
### List enum
```sql
select n.nspname as enum_schema,
t.typname as enum_name,
string_agg(e.enumlabel, ', ') as enum_value
from pg_type t
join pg_enum e on t.oid = e.enumtypid
join pg_catalog.pg_namespace n ON n.oid = t.typnamespace
group by enum_schema, enum_name
```
# Queries with IPs
### Top networks
```sql
CREATE TABLE ip (
id serial NOT NULL,
addr cidr NOT NULL,
hostname character varying(25) NOT NULL
);
SELECT * FROM ip WHERE NOT EXISTS
(SELECT addr FROM net n WHERE n.addr >> net.addr);
```
### Bigint to IP
```sql
create function bigint_to_inet(bigint) returns inet as
$$
select (($1>>24&255)||'.'||($1>>16&255)||'.'||($1>>8&255)||'.'||($1>>0&255))::inet
$$ language sql;
```
# Dump / Restore
### Dump All Functions (to a file)
```sql
SELECT pg_get_functiondef(f.oid) FROM pg_catalog.pg_proc f
INNER JOIN pg_catalog.pg_namespace n ON (f.pronamespace = n.oid)
WHERE n.nspname = 'public';
```
- run `\o functions.sql` first to save the output to a file or
- use `\copy (...) to`
### Dump database
```bash
pg_dump -U username -h hostname databasename > dump.sql
```
### Import info existing database
```bash
psql -d newdb -f dump.sql
```
### Dump and Restore Sperling Database
```bash
pg_dump --no-owner -U sperling_prod -h mimir1.aco.net sperling_prod > dump.sql
psql -h localhosst sperling_devel postgres -f dump.sql
```
# Major Version Upgrade on Debian
- make a snapshot/backup of the machine
- check the running clusters using `pg_lsclusters` command
- drop the new cluster (the one running the target version) `sudo -u postgres pg_dropcluster --stop 15 main`
- (optional) if you are ssh-ing from a macOS/Item2 the LC\_CTYPE is wrongly set
- run `export LC_CTYPE=en_US.UTF-8 export LC_ALL=en_US.UTF-8`
- upgrade the old cluster `sudo -u postgres pg_upgradecluster 13 main`
- check the running clusters using `pg_lsclusters` command
- drop the old cluster (be sure the upgrade was successful) `sudo -u postgres pg_dropcluster 13 main`
- uninstall old postgresql packages