media-downloader/docs/POSTGRESQL_MIGRATION.md

SQLite to PostgreSQL Migration Guide

Overview

This document provides a comprehensive guide for migrating the media-downloader application from SQLite to PostgreSQL.

Migration Statistics

Metric	Count
Total Tables	53
Files Requiring Changes	40+
INSERT OR IGNORE/REPLACE	60+ occurrences
datetime() functions	50+ occurrences
PRAGMA statements	30+ occurrences
AUTOINCREMENT columns	50+ occurrences
GROUP_CONCAT functions	5 occurrences
strftime() functions	10+ occurrences

---

Table of Contents

1. Schema Changes
2. Connection Pool Changes
3. SQL Syntax Conversions
4. File-by-File Changes
5. Migration Checklist
6. Data Migration Script

---

1. Schema Changes

1.1 PRIMARY KEY AUTOINCREMENT → SERIAL

SQLite:

id INTEGER PRIMARY KEY AUTOINCREMENT

PostgreSQL:

id SERIAL PRIMARY KEY

Or for larger tables:

id BIGSERIAL PRIMARY KEY

1.2 BOOLEAN Columns

SQLite stores booleans as integers (0/1). PostgreSQL has native BOOLEAN type.

SQLite	PostgreSQL
has_images BOOLEAN DEFAULT 0	has_images BOOLEAN DEFAULT false
enabled INTEGER DEFAULT 1	enabled BOOLEAN DEFAULT true
active BOOLEAN DEFAULT 1	active BOOLEAN DEFAULT true

1.3 BLOB → BYTEA

SQLite:

thumbnail_data BLOB

PostgreSQL:

thumbnail_data BYTEA

1.4 TEXT/JSON Fields

Consider using PostgreSQL's native JSONB for better query performance:

-- SQLite
metadata TEXT  -- stores JSON as string

-- PostgreSQL (recommended)
metadata JSONB

1.5 Singleton Tables (CHECK constraint)

These work identically in both databases - no changes needed:

id INTEGER PRIMARY KEY CHECK (id = 1)

---

2. Connection Pool Changes

2.1 Current SQLite Pool (unified_database.py)

The DatabasePool class needs to be rewritten for PostgreSQL.

Current SQLite:

import sqlite3

class DatabasePool:
    def __init__(self, db_path: str, pool_size: int = 20):
        for _ in range(pool_size):
            conn = sqlite3.connect(
                db_path,
                check_same_thread=False,
                timeout=30.0,
                isolation_level=None
            )
            conn.row_factory = sqlite3.Row
            conn.execute("PRAGMA journal_mode=WAL")
            # ... other PRAGMA statements

PostgreSQL Replacement:

import psycopg2
from psycopg2 import pool
from psycopg2.extras import RealDictCursor

class DatabasePool:
    def __init__(self, dsn: str, pool_size: int = 20):
        self.pool = psycopg2.pool.ThreadedConnectionPool(
            minconn=5,
            maxconn=pool_size,
            dsn=dsn,
            cursor_factory=RealDictCursor
        )

    @contextmanager
    def get_connection(self, for_write=False):
        conn = self.pool.getconn()
        try:
            yield conn
            if for_write:
                conn.commit()
        except Exception:
            conn.rollback()
            raise
        finally:
            self.pool.putconn(conn)

2.2 Remove All PRAGMA Statements

PRAGMA is SQLite-specific. Remove all instances:

File	Lines	PRAGMA Statement	Action
unified_database.py	82-88	journal_mode, synchronous, cache_size, etc.	Remove
unified_database.py	128	wal_checkpoint	Remove
unified_database.py	148-151	journal_mode, synchronous, busy_timeout	Remove
unified_database.py	197-198	busy_timeout, journal_mode	Remove
unified_database.py	223-224	journal_mode, busy_timeout	Remove
unified_database.py	233-236	journal_mode, busy_timeout, synchronous, foreign_keys	Remove
unified_database.py	616-619	journal_mode, synchronous, cache_size, temp_store	Remove
forum_downloader.py	1361-1362	journal_mode, synchronous	Remove
thumbnail_cache_builder.py	59, 201, 232, 260, 273	journal_mode	Remove
media.py	216	journal_mode	Remove
scheduler.py	111-113	journal_mode, busy_timeout, synchronous	Remove
universal_logger.py	204	busy_timeout	Remove

Note: PRAGMA table_info() can be replaced with PostgreSQL's information_schema:

-- SQLite
PRAGMA table_info(table_name)

-- PostgreSQL
SELECT column_name, data_type, is_nullable
FROM information_schema.columns
WHERE table_name = 'table_name'

---

3. SQL Syntax Conversions

3.1 INSERT OR IGNORE → ON CONFLICT DO NOTHING

SQLite:

INSERT OR IGNORE INTO table (col1, col2) VALUES (?, ?)

PostgreSQL:

INSERT INTO table (col1, col2) VALUES ($1, $2)
ON CONFLICT DO NOTHING

Or with explicit conflict target:

INSERT INTO table (col1, col2) VALUES ($1, $2)
ON CONFLICT (col1) DO NOTHING

3.2 INSERT OR REPLACE → ON CONFLICT DO UPDATE

SQLite:

INSERT OR REPLACE INTO table (id, col1, col2) VALUES (?, ?, ?)

PostgreSQL:

INSERT INTO table (id, col1, col2) VALUES ($1, $2, $3)
ON CONFLICT (id) DO UPDATE SET
    col1 = EXCLUDED.col1,
    col2 = EXCLUDED.col2

3.3 datetime() Functions

SQLite	PostgreSQL
datetime('now')	NOW() or CURRENT_TIMESTAMP
datetime('now', '-7 days')	NOW() - INTERVAL '7 days'
datetime('now', '-24 hours')	NOW() - INTERVAL '24 hours'
datetime('now', '+30 days')	NOW() + INTERVAL '30 days'
datetime('now', ? || ' days')	NOW() + (INTERVAL '1 day' * $1)
date('now')	CURRENT_DATE
date('now', '-30 days')	CURRENT_DATE - INTERVAL '30 days'

3.4 strftime() → TO_CHAR() / EXTRACT()

SQLite	PostgreSQL
strftime('%Y', col)	TO_CHAR(col, 'YYYY') or EXTRACT(YEAR FROM col)
strftime('%m', col)	TO_CHAR(col, 'MM') or EXTRACT(MONTH FROM col)
strftime('%d', col)	TO_CHAR(col, 'DD') or EXTRACT(DAY FROM col)
strftime('%H', col)	TO_CHAR(col, 'HH24') or EXTRACT(HOUR FROM col)
strftime('%Y-%m-%d', col)	TO_CHAR(col, 'YYYY-MM-DD')
strftime('%Y-W%W', col)	TO_CHAR(col, 'IYYY-"W"IW')

3.5 GROUP_CONCAT() → STRING_AGG()

SQLite:

GROUP_CONCAT(column, ', ')
GROUP_CONCAT(DISTINCT column)

PostgreSQL:

STRING_AGG(column, ', ')
STRING_AGG(DISTINCT column::text, ',')

3.6 IFNULL() → COALESCE()

SQLite:

IFNULL(column, 'default')

PostgreSQL:

COALESCE(column, 'default')

Note: The codebase already uses COALESCE in most places.

3.7 Parameter Placeholders

SQLite (sqlite3):

cursor.execute("SELECT * FROM table WHERE id = ?", (id,))

PostgreSQL (psycopg2):

cursor.execute("SELECT * FROM table WHERE id = %s", (id,))

3.8 Last Insert ID

SQLite:

cursor.execute("INSERT INTO table ...")
id = cursor.lastrowid

PostgreSQL:

cursor.execute("INSERT INTO table ... RETURNING id")
id = cursor.fetchone()[0]

3.9 LIKE Case Sensitivity

SQLite: LIKE is case-insensitive by default PostgreSQL: LIKE is case-sensitive

-- SQLite (case-insensitive)
WHERE filename LIKE '%pattern%'

-- PostgreSQL (case-insensitive)
WHERE filename ILIKE '%pattern%'
-- OR
WHERE LOWER(filename) LIKE LOWER('%pattern%')

---

4. File-by-File Changes

4.1 Core Database Module

/opt/media-downloader/modules/unified_database.py

Line(s)	Current	Change To	Notes
82-88	PRAGMA statements	Remove	PostgreSQL doesn't use PRAGMA
128	PRAGMA wal_checkpoint	Remove
148-151	PRAGMA statements	Remove
197-198	PRAGMA statements	Remove
223-224	PRAGMA statements	Remove
233-236	PRAGMA statements	Remove
241	INTEGER PRIMARY KEY AUTOINCREMENT	SERIAL PRIMARY KEY
326, 347, 367, etc.	INTEGER PRIMARY KEY AUTOINCREMENT	SERIAL PRIMARY KEY	~50 tables
500	INSERT OR IGNORE	ON CONFLICT DO NOTHING
510	INSERT OR IGNORE	ON CONFLICT DO NOTHING
616-619	PRAGMA statements	Remove
622-665	Triggers with datetime('now')	Use NOW()	4 triggers
807	INSERT OR IGNORE	ON CONFLICT DO NOTHING
877	INSERT OR IGNORE	ON CONFLICT DO NOTHING
940	INSERT OR IGNORE	ON CONFLICT DO NOTHING
1116	INSERT OR IGNORE	ON CONFLICT DO NOTHING
1119, 1141, 1151, 1239	PRAGMA table_info	Use information_schema
1207	INSERT OR IGNORE	ON CONFLICT DO NOTHING
1309	INSERT OR IGNORE	ON CONFLICT DO NOTHING
1374	INSERT OR IGNORE	ON CONFLICT DO NOTHING
1549-1563	INSERT OR IGNORE	ON CONFLICT DO NOTHING
1806	INSERT OR IGNORE	ON CONFLICT DO NOTHING
1841	INSERT OR IGNORE	ON CONFLICT DO NOTHING
2293	INSERT OR IGNORE	ON CONFLICT DO NOTHING
3176	INSERT OR IGNORE	ON CONFLICT DO NOTHING

4.2 Paid Content Module

/opt/media-downloader/modules/paid_content/db_adapter.py

Line	Current	Change To
132	INSERT OR IGNORE INTO paid_content_config	ON CONFLICT DO NOTHING
1346	INSERT OR REPLACE INTO paid_content_posts	ON CONFLICT DO UPDATE
1436	datetime('now', '-7 days')	NOW() - INTERVAL '7 days'
1699	INSERT OR IGNORE INTO paid_content_post_tags	ON CONFLICT DO NOTHING
1727	INSERT OR IGNORE INTO paid_content_post_tags	ON CONFLICT DO NOTHING

4.3 Forum Module

/opt/media-downloader/modules/forum_db_adapter.py

Line	Current	Change To
88	INSERT OR IGNORE INTO forum_threads	ON CONFLICT DO NOTHING
179	INSERT OR REPLACE INTO forum_posts	ON CONFLICT DO UPDATE
252	INSERT OR REPLACE INTO search_monitors	ON CONFLICT DO UPDATE
454	datetime('now', ? || ' days')	NOW() + (INTERVAL '1 day' * $1)
462	datetime('now', ? || ' days')	NOW() + (INTERVAL '1 day' * $1)
470	datetime('now')	NOW()

/opt/media-downloader/modules/forum_downloader.py

Line	Current	Change To
1324	INTEGER PRIMARY KEY AUTOINCREMENT	SERIAL PRIMARY KEY
1361-1362	PRAGMA statements	Remove
1373	datetime('now', '-90 days')	NOW() - INTERVAL '90 days'
1385	datetime('now')	NOW()
1397	datetime('now', '-180 days')	NOW() - INTERVAL '180 days'
2608	INSERT OR IGNORE INTO threads	ON CONFLICT DO NOTHING
2658	INSERT OR IGNORE INTO search_results	ON CONFLICT DO NOTHING
2846	INSERT OR REPLACE INTO threads	ON CONFLICT DO UPDATE
2912	INSERT OR REPLACE INTO posts	ON CONFLICT DO UPDATE

4.4 Backend Routers

/opt/media-downloader/web/backend/routers/media.py

Line	Current	Change To
216	PRAGMA journal_mode=WAL	Remove
250	INSERT OR REPLACE INTO thumbnails	ON CONFLICT DO UPDATE
318	INSERT OR REPLACE INTO thumbnails	ON CONFLICT DO UPDATE
1334, 1338, 1391, 1395	DATE() functions	Compatible, but review

/opt/media-downloader/web/backend/routers/video_queue.py

Line	Current	Change To
410	datetime('now', '-24 hours')	NOW() - INTERVAL '24 hours'
546	INSERT OR REPLACE INTO settings	ON CONFLICT DO UPDATE
553	INSERT OR REPLACE INTO settings	ON CONFLICT DO UPDATE
676	INSERT OR REPLACE INTO settings	ON CONFLICT DO UPDATE
720	cursor.lastrowid	Use RETURNING clause
1269	INSERT OR REPLACE INTO thumbnails	ON CONFLICT DO UPDATE

/opt/media-downloader/web/backend/routers/downloads.py

Line	Current	Change To
353-354	datetime('now', '-1 day')	NOW() - INTERVAL '1 day'
1214	datetime('now', '-30 days')	NOW() - INTERVAL '30 days'
1285	strftime('%H', download_date)	EXTRACT(HOUR FROM download_date)
1287	datetime('now', '-7 days')	NOW() - INTERVAL '7 days'
1298-1299	datetime('now', '-7/-14 days')	NOW() - INTERVAL '...'
1304	datetime('now', '-14 days')	NOW() - INTERVAL '14 days'

/opt/media-downloader/web/backend/routers/recycle.py

Line	Current	Change To
611	INSERT OR REPLACE INTO thumbnails	ON CONFLICT DO UPDATE

/opt/media-downloader/web/backend/routers/appearances.py

Line	Current	Change To
344	GROUP_CONCAT(DISTINCT credit_type)	STRING_AGG(DISTINCT credit_type, ',')
348, 366	datetime('now')	NOW()
529	datetime('now', '-7 days')	NOW() - INTERVAL '7 days'
531	datetime('now', '-30 days')	NOW() - INTERVAL '30 days'
552	GROUP_CONCAT(DISTINCT credit_type)	STRING_AGG(DISTINCT credit_type, ',')
741-742	GROUP_CONCAT(DISTINCT ...)	STRING_AGG(DISTINCT ..., ',')

/opt/media-downloader/web/backend/routers/celebrity.py

Line	Current	Change To
623	cursor.lastrowid	Use RETURNING clause
907	cursor.lastrowid	Use RETURNING clause
936-946	INSERT OR IGNORE	ON CONFLICT DO NOTHING
948-949	cursor.lastrowid	Use RETURNING clause
1166-1189	INSERT OR IGNORE	ON CONFLICT DO NOTHING

/opt/media-downloader/web/backend/routers/video.py

Line	Current	Change To
877-880	INSERT OR REPLACE INTO video_preview_list	ON CONFLICT DO UPDATE
1610-1612	INSERT OR REPLACE INTO settings	ON CONFLICT DO UPDATE

/opt/media-downloader/web/backend/routers/config.py

Line	Current	Change To
554	datetime('now', '-1 day')	NOW() - INTERVAL '1 day'
698	INSERT OR IGNORE INTO appearance_config	ON CONFLICT DO NOTHING

/opt/media-downloader/web/backend/routers/discovery.py

Line	Current	Change To
833	datetime('now', '-1 day')	NOW() - INTERVAL '1 day'
840	datetime('now', '-7 days')	NOW() - INTERVAL '7 days'
846	datetime('now', '-1 day')	NOW() - INTERVAL '1 day'
852	datetime('now', '-7 days')	NOW() - INTERVAL '7 days'

/opt/media-downloader/web/backend/routers/stats.py

Line	Current	Change To
107-115	DATE('now', '-30 days')	CURRENT_DATE - INTERVAL '30 days'
167-170	DATE('now', '-7 days')	CURRENT_DATE - INTERVAL '7 days'

/opt/media-downloader/web/backend/routers/face.py

Line	Current	Change To
513	DATE('now', '-30 days')	CURRENT_DATE - INTERVAL '30 days'

4.5 Other Modules

/opt/media-downloader/modules/download_manager.py

Line	Current	Change To
138	INTEGER PRIMARY KEY AUTOINCREMENT	SERIAL PRIMARY KEY
794	INSERT OR REPLACE INTO downloads	ON CONFLICT DO UPDATE
905	datetime('now', '-' || ? || ' days')	NOW() - (INTERVAL '1 day' * $1)

/opt/media-downloader/modules/scheduler.py

Line	Current	Change To
111-113	PRAGMA statements	Remove
285	INSERT OR REPLACE INTO scheduler_state	ON CONFLICT DO UPDATE
324	INSERT OR REPLACE INTO scheduler_state	ON CONFLICT DO UPDATE

/opt/media-downloader/modules/activity_status.py

Line	Current	Change To
48	INTEGER PRIMARY KEY CHECK (id = 1)	Keep (compatible)
64	INSERT OR IGNORE INTO activity_status	ON CONFLICT DO NOTHING
253	INSERT OR REPLACE INTO background_task_status	ON CONFLICT DO UPDATE

/opt/media-downloader/modules/settings_manager.py

Line	Current	Change To
113	INSERT OR REPLACE INTO settings	ON CONFLICT DO UPDATE

/opt/media-downloader/modules/discovery_system.py

Line	Current	Change To
249	INSERT OR IGNORE INTO file_tags	ON CONFLICT DO NOTHING
327	INSERT OR IGNORE INTO file_tags	ON CONFLICT DO NOTHING
695	INSERT OR IGNORE INTO collection_files	ON CONFLICT DO NOTHING
815, 886, 890, etc.	strftime()	TO_CHAR()

/opt/media-downloader/modules/semantic_search.py

Line	Current	Change To
286	INSERT OR REPLACE INTO content_embeddings	ON CONFLICT DO UPDATE

/opt/media-downloader/modules/instagram_repost_detector.py

Line	Current	Change To
445	INSERT OR REPLACE INTO repost_fetch_cache	ON CONFLICT DO UPDATE
708	INTEGER PRIMARY KEY AUTOINCREMENT	SERIAL PRIMARY KEY

/opt/media-downloader/modules/easynews_monitor.py

Line	Current	Change To
95	INTEGER PRIMARY KEY CHECK (id = 1)	Keep (compatible)
116	PRAGMA table_info	Use information_schema
123	INSERT OR IGNORE INTO easynews_config	ON CONFLICT DO NOTHING
130, 349	INTEGER PRIMARY KEY AUTOINCREMENT	SERIAL PRIMARY KEY

/opt/media-downloader/modules/youtube_channel_monitor.py

Line	Current	Change To
970	INSERT OR IGNORE INTO youtube_monitor_history	ON CONFLICT DO NOTHING

/opt/media-downloader/modules/face_recognition_module.py

Line	Current	Change To
175, 1249, 1419, 1679	PRAGMA table_info	Use information_schema
1257	datetime('now')	NOW()
1333	datetime('now')	NOW()

/opt/media-downloader/modules/thumbnail_cache_builder.py

Line	Current	Change To
59, 201, 232, 260, 273	PRAGMA journal_mode=WAL	Remove
203	INSERT OR REPLACE INTO thumbnails	ON CONFLICT DO UPDATE
234	INSERT OR REPLACE INTO media_metadata	ON CONFLICT DO UPDATE

/opt/media-downloader/modules/universal_video_downloader.py

Line	Current	Change To
1058	INSERT OR REPLACE INTO downloads	ON CONFLICT DO UPDATE
1344	INSERT OR IGNORE INTO downloads	ON CONFLICT DO NOTHING

/opt/media-downloader/modules/move_module.py

Line	Current	Change To
276	INSERT OR REPLACE INTO thumbnails	ON CONFLICT DO UPDATE

---

5. Migration Checklist

Phase 1: Preparation

• Set up PostgreSQL server
• Create database and user with appropriate permissions
• Install psycopg2 Python package
• Back up existing SQLite database

Phase 2: Schema Migration

• Convert all INTEGER PRIMARY KEY AUTOINCREMENT to SERIAL PRIMARY KEY
• Convert BOOLEAN DEFAULT 0/1 to BOOLEAN DEFAULT false/true
• Convert BLOB columns to BYTEA
• Consider converting TEXT JSON columns to JSONB
• Create all indexes (same syntax works)
• Create all foreign key constraints
• Convert triggers to use NOW() instead of datetime('now')

Phase 3: Connection Layer

• Replace sqlite3 imports with psycopg2
• Rewrite DatabasePool class for PostgreSQL
• Remove all PRAGMA statements
• Update connection string handling

Phase 4: Query Migration

• Replace all INSERT OR IGNORE with ON CONFLICT DO NOTHING
• Replace all INSERT OR REPLACE with ON CONFLICT DO UPDATE
• Replace all datetime('now', ...) with NOW() - INTERVAL '...'
• Replace all strftime() with TO_CHAR() or EXTRACT()
• Replace all GROUP_CONCAT() with STRING_AGG()
• Replace all IFNULL() with COALESCE() (mostly done)
• Replace all ? parameter placeholders with %s
• Replace all cursor.lastrowid with RETURNING clause
• Review all LIKE operators for case sensitivity

Phase 5: Data Migration

• Export data from SQLite
• Transform data types as needed
• Import into PostgreSQL
• Verify row counts match
• Verify data integrity

Phase 6: Testing

• Test all database operations
• Test date calculations
• Test upsert operations
• Test concurrent access
• Performance testing
• Integration testing with full application

---

6. Data Migration Script

#!/usr/bin/env python3
"""
SQLite to PostgreSQL Data Migration Script
"""

import sqlite3
import psycopg2
from psycopg2.extras import execute_values

# Configuration
SQLITE_PATH = '/opt/media-downloader/database/media_downloader.db'
PG_DSN = 'postgresql://user:password@localhost/media_downloader'

# Tables to migrate (in order due to foreign keys)
TABLES = [
    'downloads',
    'forum_threads',
    'forum_posts',
    'search_monitors',
    'scheduler_state',
    'thread_check_history',
    'download_queue',
    'notifications',
    'recycle_bin',
    'instagram_perceptual_hashes',
    'file_inventory',
    'video_downloads',
    'video_preview_list',
    'tags',
    'file_tags',
    'smart_folders',
    'collections',
    'collection_files',
    'content_embeddings',
    'discovery_scan_queue',
    'user_preferences',
    'scrapers',
    'error_log',
    'error_tracking',
    'celebrity_profiles',
    'celebrity_search_presets',
    'celebrity_discovered_videos',
    'celebrity_appearances',
    'appearance_notifications',
    'appearance_config',
    'video_download_queue',
    'youtube_monitor_settings',
    'youtube_channel_monitors',
    'youtube_monitor_history',
    'easynews_config',
    'easynews_searches',
    'easynews_results',
    'paid_content_services',
    'paid_content_identities',
    'paid_content_creators',
    'paid_content_posts',
    'paid_content_attachments',
    'paid_content_embeds',
    'paid_content_favorites',
    'paid_content_download_history',
    'paid_content_notifications',
    'paid_content_config',
    'paid_content_recycle_bin',
    'paid_content_tags',
    'paid_content_post_tags',
    'key_value_store',
]

def migrate_table(sqlite_conn, pg_conn, table_name):
    """Migrate a single table from SQLite to PostgreSQL"""
    sqlite_cursor = sqlite_conn.cursor()
    pg_cursor = pg_conn.cursor()

    # Get column names
    sqlite_cursor.execute(f"PRAGMA table_info({table_name})")
    columns = [row[1] for row in sqlite_cursor.fetchall()]

    # Fetch all data
    sqlite_cursor.execute(f"SELECT * FROM {table_name}")
    rows = sqlite_cursor.fetchall()

    if not rows:
        print(f"  {table_name}: No data to migrate")
        return

    # Build INSERT statement
    col_names = ', '.join(columns)
    placeholders = ', '.join(['%s'] * len(columns))

    # Use execute_values for batch insert
    insert_sql = f"INSERT INTO {table_name} ({col_names}) VALUES %s ON CONFLICT DO NOTHING"

    try:
        execute_values(pg_cursor, insert_sql, rows)
        pg_conn.commit()
        print(f"  {table_name}: Migrated {len(rows)} rows")
    except Exception as e:
        pg_conn.rollback()
        print(f"  {table_name}: ERROR - {e}")

def main():
    # Connect to both databases
    sqlite_conn = sqlite3.connect(SQLITE_PATH)
    pg_conn = psycopg2.connect(PG_DSN)

    print("Starting migration...")

    for table in TABLES:
        migrate_table(sqlite_conn, pg_conn, table)

    # Reset sequences for SERIAL columns
    pg_cursor = pg_conn.cursor()
    for table in TABLES:
        try:
            pg_cursor.execute(f"""
                SELECT setval(pg_get_serial_sequence('{table}', 'id'),
                              COALESCE(MAX(id), 1))
                FROM {table}
            """)
        except:
            pass  # Table might not have id column
    pg_conn.commit()

    sqlite_conn.close()
    pg_conn.close()

    print("Migration complete!")

if __name__ == '__main__':
    main()

---

Notes and Considerations

Performance

• PostgreSQL handles concurrent access better than SQLite
• Consider adding appropriate indexes after migration
• Use connection pooling (already implemented)
• Consider using JSONB for metadata fields

Transaction Isolation

• PostgreSQL has different default isolation levels
• Review transaction handling in critical operations

Backup Strategy

• Keep SQLite database as backup during transition
• Test rollback procedures

Monitoring

• Monitor query performance after migration
• Watch for deadlocks with concurrent writes
• Monitor connection pool utilization

---

Document Version: 1.0 Last Updated: 2026-01-30 Generated by: Claude Code Migration Analysis