Vaishnavi Prabakaran wrote:
> Yes, I have created a new patch entry into the commitfest 2017-03 and
> attached the latest patch with this e-mail.
Please find attached a companion patch implementing the batch API in
pgbench, exposed as \beginbatch and \endbatch meta-commands
(without documentation).
The idea for now is to make it easier to exercise the API and test
how batching performs. I guess I'll submit the patch separately in
a future CF, depending on when/if the libpq patch goes in.
While developing this, I noted a few things with 0001-v4:
1. lack of initialization for count in PQbatchQueueCount.
Trivial fix:
--- a/src/interfaces/libpq/fe-exec.c
+++ b/src/interfaces/libpq/fe-exec.c
@@ -1874,7 +1874,7 @@ PQisBusy(PGconn *conn)
int
PQbatchQueueCount(PGconn *conn)
{
- int count;
+ int count = 0;
PGcommandQueueEntry *entry;
2. misleading error message in PQexecStart. It gets called by a few other
functions than PQexec, such as PQprepare. As I understand it, the intent
here is to forbid the synchronous functions in batch mode, so this error
message should not single out PQexec.
@@ -1932,6 +2425,13 @@ PQexecStart(PGconn *conn)
if (!conn)
return false;
+ if (conn->asyncStatus == PGASYNC_QUEUED || conn->batch_status !=
PQBATCH_MODE_OFF)
+ {
+ printfPQExpBuffer(&conn->errorMessage,
+ libpq_gettext("cannot
PQexec in batch mode\n"));
+ return false;
+ }
+
3. In relation to #2, PQsendQuery() is not forbidden in batch mode
although I don't think it can work with it, as it's based on the old
protocol.
Best regards,
--
Daniel Vérité
PostgreSQL-powered mailer: http://www.manitou-mail.org
Twitter: @DanielVerite
diff --git a/src/bin/pgbench/pgbench.c b/src/bin/pgbench/pgbench.c
index f6cb5d4..9b2fce8 100644
--- a/src/bin/pgbench/pgbench.c
+++ b/src/bin/pgbench/pgbench.c
@@ -269,7 +269,8 @@ typedef enum
*
* CSTATE_START_COMMAND starts the execution of a command. On a SQL
* command, the command is sent to the server, and we move to
- * CSTATE_WAIT_RESULT state. On a \sleep meta-command, the timer is
set,
+ * CSTATE_WAIT_RESULT state unless in batch mode.
+ * On a \sleep meta-command, the timer is set,
* and we enter the CSTATE_SLEEP state to wait for it to expire. Other
* meta-commands are executed immediately.
*
@@ -1882,11 +1883,24 @@ sendCommand(CState *st, Command *command)
if (commands[j]->type != SQL_COMMAND)
continue;
preparedStatementName(name, st->use_file, j);
- res = PQprepare(st->con, name,
- commands[j]->argv[0],
commands[j]->argc - 1, NULL);
- if (PQresultStatus(res) != PGRES_COMMAND_OK)
- fprintf(stderr, "%s",
PQerrorMessage(st->con));
- PQclear(res);
+ if (PQbatchStatus(st->con) != PQBATCH_MODE_ON)
+ {
+ res = PQprepare(st->con, name,
+
commands[j]->argv[0], commands[j]->argc - 1, NULL);
+ if (PQresultStatus(res) !=
PGRES_COMMAND_OK)
+ fprintf(stderr, "%s",
PQerrorMessage(st->con));
+ PQclear(res);
+ }
+ else
+ {
+ /*
+ * In batch mode, we use asynchronous
functions. If a server-side
+ * error occurs, it will be processed
later among the other results.
+ */
+ if (!PQsendPrepare(st->con, name,
+
commands[j]->argv[0], commands[j]->argc - 1, NULL))
+ fprintf(stderr, "%s",
PQerrorMessage(st->con));
+ }
}
st->prepared[st->use_file] = true;
}
@@ -2165,7 +2179,13 @@ doCustom(TState *thread, CState *st, StatsData *agg)
return;
}
else
- st->state = CSTATE_WAIT_RESULT;
+ {
+ /* Wait for results, unless in
batch mode */
+ if (PQbatchStatus(st->con) !=
PQBATCH_MODE_ON)
+ st->state =
CSTATE_WAIT_RESULT;
+ else
+ st->state =
CSTATE_END_COMMAND;
+ }
}
else if (command->type == META_COMMAND)
{
@@ -2207,7 +2227,47 @@ doCustom(TState *thread, CState *st, StatsData *agg)
}
else
{
- if (pg_strcasecmp(argv[0],
"set") == 0)
+ if (pg_strcasecmp(argv[0],
"beginbatch") == 0)
+ {
+ /*
+ * In batch mode, we
use a workflow based on libpq batch
+ * functions.
+ */
+ if (querymode ==
QUERY_SIMPLE)
+ {
+
commandFailed(st, "cannot use batch mode with the simple query protocol");
+ st->state =
CSTATE_ABORTED;
+ break;
+ }
+
+ if
(PQbatchStatus(st->con) != PQBATCH_MODE_OFF)
+ {
+
commandFailed(st, "already in batch mode");
+ break;
+ }
+ PQbatchBegin(st->con);
+ }
+ else if (pg_strcasecmp(argv[0],
"endbatch") == 0)
+ {
+ if
(PQbatchStatus(st->con) != PQBATCH_MODE_ON)
+ {
+
commandFailed(st, "not in batch mode");
+ break;
+ }
+ if
(!PQbatchQueueSync(st->con))
+ {
+
commandFailed(st, "failed to end the batch");
+ st->state =
CSTATE_ABORTED;
+ break;
+ }
+ if (PQbatchEnd(st->con)
== 0)
+ {
+ /* collect
pending results before getting out of batch mode */
+ st->state =
CSTATE_WAIT_RESULT;
+ break;
+ }
+ }
+ else if (pg_strcasecmp(argv[0],
"set") == 0)
{
PgBenchExpr *expr =
command->expr;
PgBenchValue result;
@@ -2279,6 +2339,7 @@ doCustom(TState *thread, CState *st, StatsData *agg)
}
break;
+
/*
* Wait for the current SQL command to complete
*/
@@ -2295,6 +2356,13 @@ doCustom(TState *thread, CState *st, StatsData *agg)
if (PQisBusy(st->con))
return; /* don't have the whole
result yet */
+ if (PQbatchStatus(st->con) == PQBATCH_MODE_ON &&
+ !PQbatchQueueProcess(st->con))
+ {
+ /* no complete result yet in batch
mode*/
+ return;
+ }
+
/*
* Read and discard the query result;
*/
@@ -2307,7 +2375,22 @@ doCustom(TState *thread, CState *st, StatsData *agg)
/* OK */
PQclear(res);
discard_response(st);
- st->state = CSTATE_END_COMMAND;
+ /*
+ * In non-batch mode, only one
result per command is expected.
+ * In batch mode, keep waiting
for results until getting
+ * PGRES_BATCH_END.
+ */
+ if (PQbatchStatus(st->con) !=
PQBATCH_MODE_ON)
+ st->state =
CSTATE_END_COMMAND;
+ break;
+ case PGRES_BATCH_END:
+ if (PQbatchEnd(st->con) == 1)
+ {
+ /* all results
collected, exit out of command and batch mode */
+ st->state =
CSTATE_END_COMMAND;
+ }
+ else
+ fprintf(stderr, "client
%d to exit batch mode", st->id);
break;
default:
commandFailed(st,
PQerrorMessage(st->con));
@@ -3173,6 +3256,13 @@ process_backslash_command(PsqlScanState sstate, const
char *source)
syntax_error(source, lineno, my_command->line,
my_command->argv[0],
"missing command", NULL, -1);
}
+ else if (pg_strcasecmp(my_command->argv[0], "beginbatch") == 0 ||
+ pg_strcasecmp(my_command->argv[0], "endbatch") == 0 )
+ {
+ if (my_command->argc > 1)
+ syntax_error(source, lineno, my_command->line,
my_command->argv[0],
+ "unexpected argument", NULL,
-1);
+ }
else
{
syntax_error(source, lineno, my_command->line,
my_command->argv[0],
--
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