postgres-patterns

Name: postgres-patterns
Author: ThibautBaissac

635stars79forks

How to install postgres-patterns?

thibautbaissac/rails_ai_agents/postgres-patterns

$npx -y skills add ThibautBaissac/rails_ai_agents --skill postgres-patterns

Installs into the current project.

Summary

PostgreSQL database patterns for query optimization, schema design, indexing, and security.

Files · 1

View on GitHub

SKILL.md

1	# PostgreSQL Patterns
2
3	Quick reference for PostgreSQL best practices. For detailed guidance, use the `database-reviewer` agent.
4
5	## When to Activate
6
7	- Writing SQL queries or migrations
8	- Designing database schemas
9	- Troubleshooting slow queries
10	- Implementing Row Level Security
11	- Setting up connection pooling
12
13	## Quick Reference
14
15	### Index Cheat Sheet
16
17	\| Query Pattern \| Index Type \| Example \|
18	\|--------------\|------------\|---------\|
19	\| `WHERE col = value` \| B-tree (default) \| `CREATE INDEX idx ON t (col)` \|
20	\| `WHERE col > value` \| B-tree \| `CREATE INDEX idx ON t (col)` \|
21	\| `WHERE a = x AND b > y` \| Composite \| `CREATE INDEX idx ON t (a, b)` \|
22	\| `WHERE jsonb @> '{}'` \| GIN \| `CREATE INDEX idx ON t USING gin (col)` \|
23	\| `WHERE tsv @@ query` \| GIN \| `CREATE INDEX idx ON t USING gin (col)` \|
24	\| Time-series ranges \| BRIN \| `CREATE INDEX idx ON t USING brin (col)` \|
25
26	### Data Type Quick Reference
27
28	\| Use Case \| Correct Type \| Avoid \|
29	\|----------\|-------------\|-------\|
30	\| IDs \| `bigint` \| `int`, random UUID \|
31	\| Strings \| `text` \| `varchar(255)` \|
32	\| Timestamps \| `timestamptz` \| `timestamp` \|
33	\| Money \| `numeric(10,2)` \| `float` \|
34	\| Flags \| `boolean` \| `varchar`, `int` \|
35
36	### Common Patterns
37
38	Composite Index Order:
39	```sql
40	-- Equality columns first, then range columns
41	CREATE INDEX idx ON orders (status, created_at);
42	-- Works for: WHERE status = 'pending' AND created_at > '2024-01-01'
43	```
44
45	Covering Index:
46	```sql
47	CREATE INDEX idx ON users (email) INCLUDE (name, created_at);
48	-- Avoids table lookup for SELECT email, name, created_at
49	```
50
51	Partial Index:
52	```sql
53	CREATE INDEX idx ON users (email) WHERE deleted_at IS NULL;
54	-- Smaller index, only includes active users
55	```
56
57	RLS Policy (Optimized):
58	```sql
59	CREATE POLICY policy ON orders
60	USING ((SELECT auth.uid()) = user_id); -- Wrap in SELECT!
61	```
62
63	UPSERT:
64	```sql
65	INSERT INTO settings (user_id, key, value)
66	VALUES (123, 'theme', 'dark')
67	ON CONFLICT (user_id, key)
68	DO UPDATE SET value = EXCLUDED.value;
69	```
70
71	Cursor Pagination:
72	```sql
73	SELECT * FROM products WHERE id > $last_id ORDER BY id LIMIT 20;
74	-- O(1) vs OFFSET which is O(n)
75	```
76
77	Queue Processing:
78	```sql
79	UPDATE jobs SET status = 'processing'
80	WHERE id = (
81	SELECT id FROM jobs WHERE status = 'pending'
82	ORDER BY created_at LIMIT 1
83	FOR UPDATE SKIP LOCKED
84	) RETURNING *;
85	```
86
87	### Anti-Pattern Detection
88
89	```sql
90	-- Find unindexed foreign keys
91	SELECT conrelid::regclass, a.attname
92	FROM pg_constraint c
93	JOIN pg_attribute a ON a.attrelid = c.conrelid AND a.attnum = ANY(c.conkey)
94	WHERE c.contype = 'f'
95	AND NOT EXISTS (
96	SELECT 1 FROM pg_index i
97	WHERE i.indrelid = c.conrelid AND a.attnum = ANY(i.indkey)
98	);
99
100	-- Find slow queries
101	SELECT query, mean_exec_time, calls
102	FROM pg_stat_statements
103	WHERE mean_exec_time > 100
104	ORDER BY mean_exec_time DESC;
105
106	-- Check table bloat
107	SELECT relname, n_dead_tup, last_vacuum
108	FROM pg_stat_user_tables
109	WHERE n_dead_tup > 1000
110	ORDER BY n_dead_tup DESC;
111	```
112
113	### Configuration Template
114
115	```sql
116	-- Connection limits (adjust for RAM)
117	ALTER SYSTEM SET max_connections = 100;
118	ALTER SYSTEM SET work_mem = '8MB';
119
120	-- Timeouts
121	ALTER SYSTEM SET idle_in_transaction_session_timeout = '30s';
122	ALTER SYSTEM SET statement_timeout = '30s';
123
124	-- Monitoring
125	CREATE EXTENSION IF NOT EXISTS pg_stat_statements;
126
127	-- Security defaults
128	REVOKE ALL ON SCHEMA public FROM public;
129
130	SELECT pg_reload_conf();
131	```
132
133	## Related
134
135	- Agent: `database-reviewer` - Full database review workflow
136	- Skill: `clickhouse-io` - ClickHouse analytics patterns
137	- Skill: `backend-patterns` - API and backend patterns

People who liked this also viewed

6 picks

Type

azure-storageAzure Storage Services including Blob Storage, File Shares, Queue Storage, Table Storage, and Data Lake. Answers questions about storage access tiers (hot, cool, cold, archive), when to use each tier,SkillsJul 2026471k1.3k
supabase-postgres-best-practicesPostgres performance optimization and best practices from Supabase. Use this skill when writing, reviewing, or optimizing Postgres queries, schema designs, or database configurations.SkillsJul 2026302k2.4k
supabaseUse when doing ANY task involving Supabase. Triggers: Supabase products (Database, Auth, Edge Functions, Realtime, Storage, Vectors, Cron, Queues); client libraries and SSR integrations (supabase-js, SkillsJul 2026179k2.4k
convex-quickstartCreates or adds Convex to an app. Use for new Convex projects, npm create convex@latest, frontend setup, env vars, or the first npx convex dev run.SkillsJul 202690k39
convex-performance-auditAudits Convex performance for reads, subscriptions, write contention, and function limits. Use for slow features, insights findings, OCC conflicts, or read amplification.SkillsJul 202689k39
convex-setup-authSets up Convex auth, identity mapping, and access control. Use for login, auth providers, users tables, protected functions, or roles in a Convex app.SkillsJul 202689k39

postgres-patterns

635stars79forks

View on GitHub

How to install postgres-patterns?

thibautbaissac/rails_ai_agents/postgres-patterns

$npx -y skills add ThibautBaissac/rails_ai_agents --skill postgres-patterns

Installs into the current project.

Summary

PostgreSQL database patterns for query optimization, schema design, indexing, and security.

Files · 1

View on GitHub

SKILL.md

1	# PostgreSQL Patterns
2
3	Quick reference for PostgreSQL best practices. For detailed guidance, use the `database-reviewer` agent.
4
5	## When to Activate
6
7	- Writing SQL queries or migrations
8	- Designing database schemas
9	- Troubleshooting slow queries
10	- Implementing Row Level Security
11	- Setting up connection pooling
12
13	## Quick Reference
14
15	### Index Cheat Sheet
16
17	\| Query Pattern \| Index Type \| Example \|
18	\|--------------\|------------\|---------\|
19	\| `WHERE col = value` \| B-tree (default) \| `CREATE INDEX idx ON t (col)` \|
20	\| `WHERE col > value` \| B-tree \| `CREATE INDEX idx ON t (col)` \|
21	\| `WHERE a = x AND b > y` \| Composite \| `CREATE INDEX idx ON t (a, b)` \|
22	\| `WHERE jsonb @> '{}'` \| GIN \| `CREATE INDEX idx ON t USING gin (col)` \|
23	\| `WHERE tsv @@ query` \| GIN \| `CREATE INDEX idx ON t USING gin (col)` \|
24	\| Time-series ranges \| BRIN \| `CREATE INDEX idx ON t USING brin (col)` \|
25
26	### Data Type Quick Reference
27
28	\| Use Case \| Correct Type \| Avoid \|
29	\|----------\|-------------\|-------\|
30	\| IDs \| `bigint` \| `int`, random UUID \|
31	\| Strings \| `text` \| `varchar(255)` \|
32	\| Timestamps \| `timestamptz` \| `timestamp` \|
33	\| Money \| `numeric(10,2)` \| `float` \|
34	\| Flags \| `boolean` \| `varchar`, `int` \|
35
36	### Common Patterns
37
38	Composite Index Order:
39	```sql
40	-- Equality columns first, then range columns
41	CREATE INDEX idx ON orders (status, created_at);
42	-- Works for: WHERE status = 'pending' AND created_at > '2024-01-01'
43	```
44
45	Covering Index:
46	```sql
47	CREATE INDEX idx ON users (email) INCLUDE (name, created_at);
48	-- Avoids table lookup for SELECT email, name, created_at
49	```
50
51	Partial Index:
52	```sql
53	CREATE INDEX idx ON users (email) WHERE deleted_at IS NULL;
54	-- Smaller index, only includes active users
55	```
56
57	RLS Policy (Optimized):
58	```sql
59	CREATE POLICY policy ON orders
60	USING ((SELECT auth.uid()) = user_id); -- Wrap in SELECT!
61	```
62
63	UPSERT:
64	```sql
65	INSERT INTO settings (user_id, key, value)
66	VALUES (123, 'theme', 'dark')
67	ON CONFLICT (user_id, key)
68	DO UPDATE SET value = EXCLUDED.value;
69	```
70
71	Cursor Pagination:
72	```sql
73	SELECT * FROM products WHERE id > $last_id ORDER BY id LIMIT 20;
74	-- O(1) vs OFFSET which is O(n)
75	```
76
77	Queue Processing:
78	```sql
79	UPDATE jobs SET status = 'processing'
80	WHERE id = (
81	SELECT id FROM jobs WHERE status = 'pending'
82	ORDER BY created_at LIMIT 1
83	FOR UPDATE SKIP LOCKED
84	) RETURNING *;
85	```
86
87	### Anti-Pattern Detection
88
89	```sql
90	-- Find unindexed foreign keys
91	SELECT conrelid::regclass, a.attname
92	FROM pg_constraint c
93	JOIN pg_attribute a ON a.attrelid = c.conrelid AND a.attnum = ANY(c.conkey)
94	WHERE c.contype = 'f'
95	AND NOT EXISTS (
96	SELECT 1 FROM pg_index i
97	WHERE i.indrelid = c.conrelid AND a.attnum = ANY(i.indkey)
98	);
99
100	-- Find slow queries
101	SELECT query, mean_exec_time, calls
102	FROM pg_stat_statements
103	WHERE mean_exec_time > 100
104	ORDER BY mean_exec_time DESC;
105
106	-- Check table bloat
107	SELECT relname, n_dead_tup, last_vacuum
108	FROM pg_stat_user_tables
109	WHERE n_dead_tup > 1000
110	ORDER BY n_dead_tup DESC;
111	```
112
113	### Configuration Template
114
115	```sql
116	-- Connection limits (adjust for RAM)
117	ALTER SYSTEM SET max_connections = 100;
118	ALTER SYSTEM SET work_mem = '8MB';
119
120	-- Timeouts
121	ALTER SYSTEM SET idle_in_transaction_session_timeout = '30s';
122	ALTER SYSTEM SET statement_timeout = '30s';
123
124	-- Monitoring
125	CREATE EXTENSION IF NOT EXISTS pg_stat_statements;
126
127	-- Security defaults
128	REVOKE ALL ON SCHEMA public FROM public;
129
130	SELECT pg_reload_conf();
131	```
132
133	## Related
134
135	- Agent: `database-reviewer` - Full database review workflow
136	- Skill: `clickhouse-io` - ClickHouse analytics patterns
137	- Skill: `backend-patterns` - API and backend patterns

People who liked this also viewed

6 picks

Type