// execStmtInAbortedTxn executes a statement in a txn that's in state
// Aborted or RestartWait. All statements cause errors except:
// - COMMIT / ROLLBACK: aborts the current transaction.
// - ROLLBACK TO SAVEPOINT / SAVEPOINT: reopens the current transaction,
// allowing it to be retried.
func (e *Executor) execStmtInAbortedTxn(
stmt parser.Statement, txnState *txnState, planMaker *planner,
) (Result, error) {
if txnState.State != Aborted && txnState.State != RestartWait {
panic("execStmtInAbortedTxn called outside of an aborted txn")
}
// TODO(andrei/cuongdo): Figure out what statements to count here.
switch s := stmt.(type) {
case *parser.CommitTransaction, *parser.RollbackTransaction:
if txnState.State == RestartWait {
return rollbackSQLTransaction(txnState, planMaker), nil
}
// Reset the state to allow new transactions to start.
// The KV txn has already been rolled back when we entered the Aborted state.
// Note: postgres replies to COMMIT of failed txn with "ROLLBACK" too.
result := Result{PGTag: (*parser.RollbackTransaction)(nil).StatementTag()}
txnState.resetStateAndTxn(NoTxn)
return result, nil
case *parser.RollbackToSavepoint, *parser.Savepoint:
// We accept both the "ROLLBACK TO SAVEPOINT cockroach_restart" and the
// "SAVEPOINT cockroach_restart" commands to indicate client intent to
// retry a transaction in a RestartWait state.
var spName string
switch n := s.(type) {
case *parser.RollbackToSavepoint:
spName = n.Savepoint
case *parser.Savepoint:
spName = n.Name
default:
panic("unreachable")
}
if err := parser.ValidateRestartCheckpoint(spName); err != nil {
return Result{Err: err}, err
}
if txnState.State == RestartWait {
// Reset the state. Txn is Open again.
txnState.State = Open
txnState.retrying = true
// TODO(andrei/cdo): add a counter for user-directed retries.
return Result{}, nil
}
err := sqlbase.NewTransactionAbortedError(fmt.Sprintf(
"SAVEPOINT %s has not been used or a non-retriable error was encountered.",
parser.RestartSavepointName))
return Result{Err: err}, err
default:
err := sqlbase.NewTransactionAbortedError("")
return Result{Err: err}, err
}
}
// execStmtInAbortedTxn executes a statement in a txn that's in state
// Aborted or RestartWait.
// Everything but COMMIT/ROLLBACK/RESTART causes errors.
func (e *Executor) execStmtInAbortedTxn(
stmt parser.Statement, txnState *txnState, planMaker *planner,
) (Result, *roachpb.Error) {
if txnState.State != Aborted && txnState.State != RestartWait {
panic("execStmtInAbortedTxn called outside of an aborted txn")
}
// TODO(andrei/cuongdo): Figure out what statements to count here.
switch s := stmt.(type) {
case *parser.CommitTransaction, *parser.RollbackTransaction:
if txnState.State == RestartWait {
return rollbackSQLTransaction(txnState, planMaker), nil
}
// Reset the state to allow new transactions to start.
// The KV txn has already been rolled back when we entered the Aborted state.
// Note: postgres replies to COMMIT of failed txn with "ROLLBACK" too.
result := Result{PGTag: (*parser.RollbackTransaction)(nil).StatementTag()}
txnState.resetStateAndTxn(NoTxn)
return result, nil
case *parser.RollbackToSavepoint:
if pErr := parser.ValidateRestartCheckpoint(s.Savepoint); pErr != nil {
return Result{PErr: pErr}, pErr
}
if txnState.State == RestartWait {
// Reset the state. Txn is Open again.
txnState.State = Open
txnState.retrying = true
// TODO(andrei/cdo): add a counter for user-directed retries.
return Result{}, nil
}
pErr := sqlErrToPErr(&errTransactionAborted{
CustomMsg: fmt.Sprintf(
"SAVEPOINT %s has not been used or a non-retriable error was encountered.",
parser.RestartSavepointName)})
return Result{PErr: pErr}, pErr
default:
pErr := sqlErrToPErr(&errTransactionAborted{})
return Result{PErr: pErr}, pErr
}
}
// execStmtInOpenTxn executes one statement in the context
// of the planner's transaction (which is assumed to exist).
// It handles statements that affect the transaction state (BEGIN, COMMIT)
// and delegates everything else to `execStmt`.
// It binds placeholders.
//
// The current transaction might be committed/rolled back when this returns.
// It might also have transitioned to the aborted or RestartWait state.
//
// Args:
// implicitTxn: set if the current transaction was implicitly
// created by the system (i.e. the client sent the statement outside of
// a transaction).
// COMMIT/ROLLBACK statements are rejected if set. Also, the transaction
// might be auto-committed in this function.
// firstInTxn: set for the first statement in a transaction. Used
// so that nested BEGIN statements are caught.
// stmtTimestamp: Used as the statement_timestamp().
//
// Returns:
// - a Result
// - an error, if any. In case of error, the result returned also reflects this error.
func (e *Executor) execStmtInOpenTxn(
stmt parser.Statement,
planMaker *planner,
implicitTxn bool,
firstInTxn bool,
txnState *txnState,
) (Result, error) {
if txnState.State != Open {
panic("execStmtInOpenTxn called outside of an open txn")
}
if planMaker.txn == nil {
panic("execStmtInOpenTxn called with the a txn not set on the planner")
}
planMaker.evalCtx.SetTxnTimestamp(txnState.sqlTimestamp)
planMaker.evalCtx.SetStmtTimestamp(e.ctx.Clock.PhysicalTime())
// TODO(cdo): Figure out how to not double count on retries.
e.updateStmtCounts(stmt)
switch s := stmt.(type) {
case *parser.BeginTransaction:
if !firstInTxn {
txnState.updateStateAndCleanupOnErr(errTransactionInProgress, e)
return Result{Err: errTransactionInProgress}, errTransactionInProgress
}
case *parser.CommitTransaction:
if implicitTxn {
return e.noTransactionHelper(txnState)
}
// CommitTransaction is executed fully here; there's no planNode for it
// and the planner is not involved at all.
res, err := commitSQLTransaction(txnState, planMaker, commit, e)
return res, err
case *parser.ReleaseSavepoint:
if implicitTxn {
return e.noTransactionHelper(txnState)
}
if err := parser.ValidateRestartCheckpoint(s.Savepoint); err != nil {
return Result{Err: err}, err
}
// ReleaseSavepoint is executed fully here; there's no planNode for it
// and the planner is not involved at all.
res, err := commitSQLTransaction(txnState, planMaker, release, e)
return res, err
case *parser.RollbackTransaction:
if implicitTxn {
return e.noTransactionHelper(txnState)
}
// RollbackTransaction is executed fully here; there's no planNode for it
// and the planner is not involved at all.
// Notice that we don't return any errors on rollback.
return rollbackSQLTransaction(txnState, planMaker), nil
case *parser.SetTransaction:
if implicitTxn {
return e.noTransactionHelper(txnState)
}
case *parser.Savepoint:
if implicitTxn {
return e.noTransactionHelper(txnState)
}
if err := parser.ValidateRestartCheckpoint(s.Name); err != nil {
return Result{Err: err}, err
}
// We want to disallow SAVEPOINTs to be issued after a transaction has
// started running, but such enforcement is problematic in the
// presence of transaction retries (since the transaction proto is
// necessarily reused). To work around this, we keep track of the
// transaction's retrying state and special-case SAVEPOINT when it is
// set.
//
// TODO(andrei): the check for retrying is a hack - we erroneously
// allow SAVEPOINT to be issued at any time during a retry, not just
// in the beginning. We should figure out how to track whether we
// started using the transaction during a retry.
if txnState.txn.Proto.IsInitialized() && !txnState.retrying {
err := fmt.Errorf("SAVEPOINT %s needs to be the first statement in a transaction",
parser.RestartSavepointName)
txnState.updateStateAndCleanupOnErr(err, e)
return Result{Err: err}, err
}
// Note that Savepoint doesn't have a corresponding plan node.
// This here is all the execution there is.
txnState.retryIntent = true
return Result{}, nil
case *parser.RollbackToSavepoint:
err := parser.ValidateRestartCheckpoint(s.Savepoint)
if err == nil {
// Can't restart if we didn't get an error first, which would've put the
// txn in a different state.
err = errNotRetriable
}
txnState.updateStateAndCleanupOnErr(err, e)
return Result{Err: err}, err
case *parser.Prepare:
err := util.UnimplementedWithIssueErrorf(7568,
"Prepared statements are supported only via the Postgres wire protocol")
txnState.updateStateAndCleanupOnErr(err, e)
return Result{Err: err}, err
case *parser.Execute:
err := util.UnimplementedWithIssueErrorf(7568,
"Executing prepared statements is supported only via the Postgres wire protocol")
txnState.updateStateAndCleanupOnErr(err, e)
return Result{Err: err}, err
case *parser.Deallocate:
if s.Name == "" {
planMaker.session.PreparedStatements.DeleteAll()
} else {
if found := planMaker.session.PreparedStatements.Delete(string(s.Name)); !found {
err := fmt.Errorf("prepared statement %s does not exist", s.Name)
txnState.updateStateAndCleanupOnErr(err, e)
return Result{Err: err}, err
}
}
return Result{PGTag: s.StatementTag()}, nil
}
if txnState.tr != nil {
txnState.tr.LazyLog(stmt, true /* sensitive */)
}
result, err := e.execStmt(stmt, planMaker, implicitTxn /* autoCommit */)
if err != nil {
if traceSQL {
log.Tracef(txnState.txn.Context, "ERROR: %v", err)
}
if txnState.tr != nil {
txnState.tr.LazyPrintf("ERROR: %v", err)
}
txnState.updateStateAndCleanupOnErr(err, e)
result = Result{Err: err}
} else if txnState.tr != nil {
tResult := &traceResult{tag: result.PGTag, count: -1}
switch result.Type {
case parser.RowsAffected:
tResult.count = result.RowsAffected
case parser.Rows:
tResult.count = len(result.Rows)
}
txnState.tr.LazyLog(tResult, false)
if traceSQL {
log.Tracef(txnState.txn.Context, "%s done", tResult)
}
}
return result, err
}
// execStmtInOpenTxn executes one statement in the context
// of the planner's transaction (which is assumed to exist).
// It handles statements that affect the transaction state (BEGIN, COMMIT)
// and delegates everything else to `execStmt`.
// It binds placeholders.
//
// The current transaction might be committed/rolled back when this returns.
// It might also have transitioned to the aborted or RestartWait state.
//
// Args:
// implicitTxn: set if the current transaction was implicitly
// created by the system (i.e. the client sent the statement outside of
// a transaction).
// COMMIT/ROLLBACK statements are rejected if set. Also, the transaction
// might be auto-committed in this function.
// firstInTxn: set for the first statement in a transaction. Used
// so that nested BEGIN statements are caught.
// stmtTimestamp: Used as the statement_timestamp().
//
// Returns:
// - a Result
// - an error, if any. In case of error, the result returned also reflects this error.
func (e *Executor) execStmtInOpenTxn(
stmt parser.Statement, planMaker *planner,
implicitTxn bool,
firstInTxn bool,
stmtTimestamp roachpb.Timestamp,
txnState *txnState) (Result, *roachpb.Error) {
if txnState.State != Open {
panic("execStmtInOpenTxn called outside of an open txn")
}
if planMaker.txn == nil {
panic("execStmtInOpenTxn called with the a txn not set on the planner")
}
planMaker.evalCtx.SetStmtTimestamp(stmtTimestamp)
// TODO(cdo): Figure out how to not double count on retries.
e.updateStmtCounts(stmt)
switch s := stmt.(type) {
case *parser.BeginTransaction:
if !firstInTxn {
txnState.resetStateAndTxn(Aborted)
pErr := roachpb.NewError(errTransactionInProgress)
return Result{PErr: pErr}, pErr
}
case *parser.CommitTransaction:
if implicitTxn {
return e.noTransactionHelper(txnState)
}
// CommitTransaction is executed fully here; there's no planNode for it
// and the planner is not involved at all.
return commitSQLTransaction(txnState, planMaker, commit, e)
case *parser.ReleaseSavepoint:
if implicitTxn {
return e.noTransactionHelper(txnState)
}
if pErr := parser.ValidateRestartCheckpoint(s.Savepoint); pErr != nil {
return Result{PErr: pErr}, pErr
}
// ReleaseSavepoint is executed fully here; there's no planNode for it
// and the planner is not involved at all.
return commitSQLTransaction(txnState, planMaker, release, e)
case *parser.RollbackTransaction:
if implicitTxn {
return e.noTransactionHelper(txnState)
}
// RollbackTransaction is executed fully here; there's no planNode for it
// and the planner is not involved at all.
// Notice that we don't return any errors on rollback.
return rollbackSQLTransaction(txnState, planMaker), nil
case *parser.SetTransaction:
if implicitTxn {
return e.noTransactionHelper(txnState)
}
case *parser.Savepoint:
if implicitTxn {
return e.noTransactionHelper(txnState)
}
if pErr := parser.ValidateRestartCheckpoint(s.Name); pErr != nil {
return Result{PErr: pErr}, pErr
}
// We check if the transaction has "started" already by looking inside the txn proto.
// The executor should not be doing that. But it's also what the planner does for
// SET TRANSACTION ISOLATION ... It feels ever more wrong here.
// TODO(andrei): find a better way to track this running state.
// TODO(andrei): the check for retrying is a hack - we erroneously allow
// SAVEPOINT to be issued at any time during a retry, not just in the
// beginning. We should figure out how to track whether we started using the
// transaction during a retry.
if txnState.txn.Proto.IsInitialized() && !txnState.retrying {
pErr := roachpb.NewError(util.Errorf(
"SAVEPOINT %s needs to be the first statement in a transaction",
parser.RestartSavepointName))
return Result{PErr: pErr}, pErr
}
// Note that Savepoint doesn't have a corresponding plan node.
// This here is all the execution there is.
txnState.retryIntent = true
return Result{}, nil
case *parser.RollbackToSavepoint:
if pErr := parser.ValidateRestartCheckpoint(s.Savepoint); pErr != nil {
return Result{PErr: pErr}, pErr
}
// Can't restart if we didn't get an error first, which would've put the
// txn in a different state.
txnState.resetStateAndTxn(Aborted)
pErr := roachpb.NewError(errNotRetriable)
return Result{PErr: pErr}, pErr
}
// Bind all the placeholder variables in the stmt to actual values.
stmt, err := parser.FillArgs(stmt, &planMaker.params)
if err != nil {
txnState.resetStateAndTxn(Aborted)
pErr := roachpb.NewError(err)
return Result{PErr: pErr}, pErr
}
if txnState.tr != nil {
txnState.tr.LazyLog(stmt, true /* sensitive */)
}
result, pErr := e.execStmt(stmt, planMaker, timeutil.Now(),
implicitTxn /* autoCommit */)
if pErr != nil {
if txnState.tr != nil {
txnState.tr.LazyPrintf("ERROR: %v", pErr)
}
txnState.updateStateAndCleanupOnErr(pErr, e)
result = Result{PErr: pErr}
} else if txnState.tr != nil {
tResult := &traceResult{tag: result.PGTag, count: -1}
switch result.Type {
case parser.RowsAffected:
tResult.count = result.RowsAffected
case parser.Rows:
tResult.count = len(result.Rows)
}
txnState.tr.LazyLog(tResult, false)
}
return result, pErr
}