All Errors

When CREATE INDEX CONCURRENTLY fails, PostgreSQL leaves behind an invalid index that consumes resources without providing query benefits. You must identify and remove the invalid index, then resolve the underlying cause before retrying index creation.

PostgreSQL indexes can become corrupted due to hardware failures, software bugs, or unexpected data issues. Use REINDEX or CREATE INDEX CONCURRENTLY to rebuild the corrupted index and restore database integrity.

This warning appears when apt finds GPG keys in the deprecated /etc/apt/trusted.gpg file instead of the modern /etc/apt/trusted.gpg.d/ directory. While not blocking updates, it indicates outdated key management that should be migrated to comply with current security practices.

The Redis MOVED error indicates that a hash slot has been moved to a different node in a Redis Cluster. This is a client-side redirection issue that occurs when a client connects to a cluster node that no longer owns the requested slot. Fixing requires using cluster-aware Redis clients or enabling cluster mode in your client library.

Redis is configured to require password authentication, but your client connected without providing credentials. This error occurs when the requirepass directive is set on the server and clients attempt to execute commands without first authenticating with the AUTH command.

This error occurs when SQLite cannot initialize the Write-Ahead Logging (WAL) shared memory region due to insufficient write permissions on the WAL or shared memory files, preventing database access even for read-only operations.

pg_restore only works with binary or directory format dumps, not plain text SQL files. Use psql to restore text dumps or recreate dumps using pg_dump with the -Fc (custom) format flag.

The "ERR crossed slot boundary" (also displayed as "CROSSSLOT Keys in request don't hash to the same slot") error occurs in Redis Cluster when a multi-key command attempts to operate on keys that hash to different hash slots. Redis Cluster divides data across 16,384 slots, and multi-key operations like MGET, MSET, and Lua scripts require all keys to reside in the same slot. Fix by using hash tags to ensure keys hash to the same slot, or by executing separate commands on each slot.

This error occurs when a Redis client sends malformed commands or receives corrupted responses that violate the RESP (Redis Serialization Protocol) format. The issue typically stems from connection problems, protocol version mismatches, improper connection pooling, or network corruption. Fix by using connection pools, enabling proper authentication, ensuring RESP2/RESP3 compatibility, and validating command formatting.

This error occurs when PostgreSQL is performing recovery after an improper shutdown or when WAL control functions are executed on a standby/replica server. Most cases resolve automatically once recovery completes.

Your PostgreSQL sequence has exhausted its maximum value and can no longer generate new IDs. This typically happens with 32-bit integer sequences that reach 2.1 billion values. Fix it by using 64-bit sequences or altering the sequence to use a larger data type.

MySQL Error 1146 (42S02) occurs when a query tries to access a table that does not exist or cannot be found. Common causes include typos in table names, case sensitivity issues on Linux, selecting the wrong database, corrupted table files, and missing InnoDB data dictionary files. Fixes involve verifying table existence, checking case sensitivity, and repairing corrupted files.

PostgreSQL "Connection does not exist" error occurs when a client tries to use or reference a connection that has been closed, terminated, or never established. Common causes include connection timeouts, server restarts, pooling misconfiguration, and referencing non-existent connections. Fixing requires verifying connection parameters, checking server status, and properly managing connection pools.

Peer authentication failed occurs when PostgreSQL tries to authenticate a connection using peer authentication (Unix socket) but the system username does not match the database username. Change the authentication method in pg_hba.conf or connect via TCP with a password.

An exclusion constraint violation occurs when you attempt to insert or update data that conflicts with an existing row according to the constraint's comparison rules. Exclusion constraints prevent overlapping or conflicting values using operators like equality or range overlap.

MySQL Error 1040 occurs when the number of concurrent client connections exceeds the server's max_connections limit. This happens due to insufficient connection limits, poor connection management, slow queries, or traffic spikes. Fix by increasing max_connections, implementing connection pooling, adjusting timeout values, and optimizing queries.

Connection exceptions in PostgreSQL occur when the client fails to establish or maintain a TCP/IP connection to the database server. This can happen due to the server not running, network issues, firewall blocking, or incorrect connection parameters.

PostgreSQL cannot start because the pg_version file is missing from the data directory. This typically occurs during upgrades, after data directory corruption, or when using an improperly initialized database cluster.

The 'LOADING Redis is loading the dataset in memory' error occurs when a client attempts to connect to a Redis server that is still initializing and loading persisted data from disk. This is a temporary state during startup or replica resynchronization that prevents commands from executing until the dataset is fully loaded.

This error occurs when connecting to Redis with an incorrect password or invalid authentication credentials. Verify the password matches your Redis configuration, check the authentication format for Redis 6.0+, and ensure special characters are properly encoded.