How to fix SQLITE_NOMEM: A malloc() failed in SQLite

const sqlite3 = require('sqlite3');
const db = new sqlite3.Database('mydb.sqlite');

try {
  // Your database operations
  db.all('SELECT * FROM users', (err, rows) => {
    if (err) console.error(err);
    // Process rows
  });
} finally {
  // Always close the database
  db.close((err) => {
    if (err) console.error('Error closing database:', err);
  });
}

import sqlite3

conn = sqlite3.connect('mydb.sqlite')
try:
    cursor = conn.cursor()
    cursor.execute('SELECT * FROM users')
    rows = cursor.fetchall()
    # Process rows
finally:
    cursor.close()
    conn.close()

sqlite3 *db;
sqlite3_stmt *stmt;

// Always finalize statements and close connections
if (stmt) sqlite3_finalize(stmt);
if (db) sqlite3_close(db);

-- Check current cache size
PRAGMA cache_size;

-- Reduce cache size before creating index
PRAGMA cache_size = 2000;  -- Default is usually -2000 (2MB)

-- Create your index
CREATE INDEX idx_users_email ON users(email);

-- Restore original cache size if needed
PRAGMA cache_size = -2000;

const PAGE_SIZE = 1000;
let offset = 0;
let hasMore = true;

while (hasMore) {
  const rows = db.prepare(
    'SELECT * FROM large_table LIMIT ? OFFSET ?'
  ).all(PAGE_SIZE, offset);

  if (rows.length === 0) {
    hasMore = false;
  } else {
    // Process this chunk
    processRows(rows);
    offset += PAGE_SIZE;
  }
}

// Set soft heap limit to 64MB
sqlite3_soft_heap_limit64(64 * 1024 * 1024);

// Set hard heap limit to 128MB
sqlite3_hard_heap_limit64(128 * 1024 * 1024);

// Before sqlite3_initialize()
sqlite3_config(SQLITE_CONFIG_MEMDB_MAXSIZE, 2147483648LL); // 2GB

-- Instead of storing the entire file:
-- CREATE TABLE documents (id INTEGER, content BLOB);

-- Store only the file path:
CREATE TABLE documents (
  id INTEGER PRIMARY KEY,
  file_path TEXT NOT NULL,
  file_size INTEGER,
  content_hash TEXT
);

import sqlite3
import zlib

conn = sqlite3.connect('mydb.sqlite')
cursor = conn.cursor()

# Compress before storing
large_text = "..." * 10000
compressed = zlib.compress(large_text.encode())
cursor.execute('INSERT INTO logs (data) VALUES (?)', (compressed,))

# Decompress when reading
cursor.execute('SELECT data FROM logs WHERE id = ?', (1,))
compressed_data = cursor.fetchone()[0]
original_text = zlib.decompress(compressed_data).decode()

// Incremental BLOB I/O
sqlite3_blob *blob;
sqlite3_blob_open(db, "main", "images", "data", rowid, 0, &blob);

// Read in chunks
char buffer[4096];
int offset = 0;
while (offset < sqlite3_blob_bytes(blob)) {
  sqlite3_blob_read(blob, buffer, sizeof(buffer), offset);
  // Process chunk
  offset += sizeof(buffer);
}

sqlite3_blob_close(blob);

CREATE VIRTUAL TABLE documents_fts4 USING fts4(title, content);

CREATE VIRTUAL TABLE documents_fts5 USING fts5(title, content);

-- Create new FTS5 table
CREATE VIRTUAL TABLE documents_fts5 USING fts5(title, content);

-- Copy data in batches to avoid memory issues
INSERT INTO documents_fts5(title, content)
SELECT title, content FROM documents_fts4 LIMIT 1000 OFFSET 0;

-- Repeat with increasing offsets until all data is migrated

-- Drop old table
DROP TABLE documents_fts4;

SELECT sqlite_version();

npm update better-sqlite3

pip install --upgrade pysqlite3-binary

# Ubuntu/Debian
sudo apt update
sudo apt install --only-upgrade sqlite3

# Download and compile latest version
wget https://www.sqlite.org/2025/sqlite-autoconf-XXXXXXX.tar.gz
tar xvfz sqlite-autoconf-XXXXXXX.tar.gz
cd sqlite-autoconf-XXXXXXX
./configure
make
sudo make install