docs/content/stable/develop/learn/transactions/transactions-errorcodes-ysql.md
Due to the strong ACID properties guaranteed by YugabyteDB, failures during transactions are inevitable. You need to design your applications to take appropriate action on failed statements to ensure they are highly available. YugabyteDB returns various error codes for errors that occur during transaction processing.
The following error codes typically occur during transaction processing.
This error occurs when certain statements that should be run outside a transaction block, typically because they have non-rollback-able side effects or do internal commits, are executed inside a transaction block. For example, issuing a BEGIN statement inside a transaction.
WARNING: 25001: there is already a transaction in progress
{{<note>}} 25001 errors are just warnings. But the code needs to be fixed to avoid future warnings. {{</note>}}
This error occurs when certain statements are executed in a read-only transaction that violate the read-only constraint. For example, modifying records inside a read-only transaction.
ERROR: 25006: cannot execute UPDATE in a read-only transaction
{{<note>}} 25006 errors are Non-retriable. Writes should be removed from the read-only transaction code. {{</note>}}
This error occurs when certain statements that should be executed in a transaction are executed outside of a transaction. For example, issuing a ROLLBACK outside a transaction.
WARNING: 25P01: there is no transaction in progress
{{<note>}} 25P01 errors are just warnings. But the code needs to be fixed to avoid future warnings. {{</note>}}
This error occurs when statements have failed inside a transaction and another statement other than COMMIT or ROLLBACK is executed.
ERROR: 25P02: current transaction is aborted, commands ignored until end of transaction block
{{<note>}}
25P02 errors are Non-retriable. Proper error handling via a try..catch block and either COMMIT or ROLLBACK should be executed appropriately.
{{</note>}}
This occurs when an application stays idle longer than idle_in_transaction_session_timeout in the middle of a transaction.
FATAL: 25P03: terminating connection due to idle-in-transaction timeout
{{<note>}} The client can reconnect to the server and retry the transaction. {{</note>}}
This error occurs when a transaction is terminated either by a COMMIT or a ROLLBACK in an invalid location. For example, when a COMMIT is issued inside a stored procedure that is called from inside a transaction.
ERROR: 2D000: invalid transaction termination
{{<note>}} 2D000 errors are Non-retriable. The transaction code needs to be fixed to get around this error. {{</note>}}
This error occurs when you try to ROLLBACK to, or RELEASE a savepoint that has not been defined.
ERROR: 3B001: savepoint "FIRST_SAVE" does not exist
{{<note>}} 3B001 errors are Non-retriable. The transaction code needs to be fixed to specify the correct savepoint name to fix this error. {{</note>}}
This error occurs when a transaction cannot be applied or progress further because of other conflicting transactions. For example, when multiple transactions are modifying the same key.
ERROR: could not serialize access due to concurrent update (...)
{{<lead link="../transactions-retries-ysql/#client-side-retry">}} Serialization failure errors can be retried by the client. See Client-side retry. {{</lead>}}
This error occurs when two or more transactions wait on each other to form a deadlock cycle. One or more of the transactions in the cycle are aborted and they fail with the following error.
ERROR: deadlock detected (...)
{{<lead link="../transactions-retries-ysql/#client-side-retry">}} Deadlock detected errors can be retried by the client. See Client-side retry. {{</lead>}}
Error codes starting with 42 typically relate to issues with SQL syntax, invalid references, or access permissions.
{{<warning>}} Retrying these errors will likely have no effect unless the respective issue is fixed. {{</warning>}}
Some of the errors are described in the following table:
| Code | Issue |
|---|---|
| 42000 | Syntax Error or Access Rule Violation (general class) |
| 42601 | Syntax Error (invalid or unexpected SQL syntax) |
| 42501 | Insufficient Privilege (lack of necessary permissions to perform the operation) |
| 42846 | Cannot Coerce (incompatible data types in an operation or query) |
| 42883 | Undefined Function (referencing a function that doesn't exist or is incorrectly called) |
| 42P01 | Undefined Table (trying to reference a table that doesn't exist) |
| 42P02 | Undefined Parameter (using a parameter that has not been defined) |
| 42P03 | Duplicate Cursor (declaring a cursor that already exists) |
| 42703 | Undefined Column (referencing a column that doesn't exist in the table) |
| 42P04 | Duplicate Database (attempting to create a database that already exists) |
| 42P05 | Duplicate Prepared Statement (trying to prepare a statement that already exists) |
| 42P06 | Duplicate Schema (attempting to create a schema that already exists) |
| 42P07 | Duplicate Table (attempting to create a table that already exists) |
| 42P08 | Ambiguous Parameter (parameter is ambiguous in context) |
| 42P09 | Ambiguous Alias (alias is ambiguous, referring to multiple possible options) |
| 42P10 | Invalid Column Reference (column reference is incorrect or inappropriate) |
| 42P11 | Invalid Cursor Definition (cursor declaration is invalid) |
| 42P12 | Invalid Database Definition (invalid database creation or operation) |
| 42P13 | Invalid Function Definition (improper definition of a function) |