What I'm going to do now is to write a patch to remove the \cset part of
the commit and post it, intending to push at some point next week.
Per your request, here is a patch which removes \cset from pgbench. Sigh.
Again, only the removal is a little deeper. This lifts the constraint
about not using empty queries in a compound statement, at the price of
some added logic to detect the last result.
--
Fabien.
diff --git a/doc/src/sgml/ref/pgbench.sgml b/doc/src/sgml/ref/pgbench.sgml
index 24833f46bc..a148138402 100644
--- a/doc/src/sgml/ref/pgbench.sgml
+++ b/doc/src/sgml/ref/pgbench.sgml
@@ -963,48 +963,6 @@ pgbench <optional> <replaceable>options</replaceable> </optional> <replaceable>d
</para>
<variablelist>
- <varlistentry id='pgbench-metacommand-cset'>
- <term>
- <literal>\cset [<replaceable>prefix</replaceable>]</literal>
- </term>
-
- <listitem>
- <para>
- This command may be used to end SQL queries, replacing an embedded
- semicolon (<literal>\;</literal>) within a compound SQL command.
- </para>
-
- <para>
- When this command is used, the preceding SQL query is expected to
- return one row, the columns of which are stored into variables named after
- column names, and prefixed with <replaceable>prefix</replaceable> if provided.
- </para>
-
- <para>
- The following example sends four queries as one compound SQL command,
- inducing one message sent at the protocol level.
- The result of the first query is stored into variable <replaceable>one</replaceable>,
- the results of the third query are stored into variables <replaceable>z_three</replaceable>
- and <replaceable>z_four</replaceable>,
- whereas the results of the other queries are discarded.
-<programlisting>
--- compound of four queries
-SELECT 1 AS one \cset
-SELECT 2 AS two \;
-SELECT 3 AS three, 4 AS four \cset z_
-SELECT 5;
-</programlisting>
- </para>
-
- <note>
- <para>
- <literal>\cset</literal> does not work when empty SQL queries appear
- within a compound SQL command.
- </para>
- </note>
- </listitem>
- </varlistentry>
-
<varlistentry id='pgbench-metacommand-gset'>
<term>
<literal>\gset [<replaceable>prefix</replaceable>]</literal>
@@ -1038,13 +996,6 @@ SELECT 1 \;
SELECT 2 AS two, 3 AS three \gset p_
</programlisting>
</para>
-
- <note>
- <para>
- <literal>\gset</literal> does not work when empty SQL queries appear
- within a compound SQL command.
- </para>
- </note>
</listitem>
</varlistentry>
diff --git a/src/bin/pgbench/pgbench.c b/src/bin/pgbench/pgbench.c
index 4789ab92ee..545c4416f1 100644
--- a/src/bin/pgbench/pgbench.c
+++ b/src/bin/pgbench/pgbench.c
@@ -490,7 +490,6 @@ typedef enum MetaCommand
META_SETSHELL, /* \setshell */
META_SHELL, /* \shell */
META_SLEEP, /* \sleep */
- META_CSET, /* \cset */
META_GSET, /* \gset */
META_IF, /* \if */
META_ELIF, /* \elif */
@@ -521,11 +520,9 @@ static const char *QUERYMODE[] = {"simple", "extended", "prepared"};
* argv Command arguments, the first of which is the command or SQL
* string itself. For SQL commands, after post-processing
* argv[0] is the same as 'lines' with variables substituted.
- * nqueries In a multi-command SQL line, the number of queries.
- * varprefix SQL commands terminated with \gset or \cset have this set
+ * varprefix SQL commands terminated with \gset have this set
* to a non NULL value. If nonempty, it's used to prefix the
* variable name that receives the value.
- * varprefix_max Allocated size of the varprefix array.
* expr Parsed expression, if needed.
* stats Time spent in this command.
*/
@@ -537,9 +534,7 @@ typedef struct Command
MetaCommand meta;
int argc;
char *argv[MAX_ARGS];
- int nqueries;
- char **varprefix;
- int varprefix_max;
+ char *varprefix;
PgBenchExpr *expr;
SimpleStats stats;
} Command;
@@ -619,7 +614,6 @@ static void doLog(TState *thread, CState *st,
static void processXactStats(TState *thread, CState *st, instr_time *now,
bool skipped, StatsData *agg);
static void pgbench_error(const char *fmt,...) pg_attribute_printf(1, 2);
-static void allocate_command_varprefix(Command *cmd, int totalqueries);
static void addScript(ParsedScript script);
static void *threadRun(void *arg);
static void finishCon(CState *st);
@@ -2614,8 +2608,6 @@ getMetaCommand(const char *cmd)
mc = META_ELSE;
else if (pg_strcasecmp(cmd, "endif") == 0)
mc = META_ENDIF;
- else if (pg_strcasecmp(cmd, "cset") == 0)
- mc = META_CSET;
else if (pg_strcasecmp(cmd, "gset") == 0)
mc = META_GSET;
else
@@ -2848,24 +2840,30 @@ sendCommand(CState *st, Command *command)
/*
* Process query response from the backend.
*
- * If varprefix is not NULL, it's the array of variable prefix names where to
- * store the results.
+ * If varprefix is not NULL, it's the variable name prefix where to store
+ * the results of the *last* command.
*
* Returns true if everything is A-OK, false if any error occurs.
*/
static bool
-readCommandResponse(CState *st, char **varprefix)
+readCommandResponse(CState *st, char *varprefix)
{
PGresult *res;
int qrynum = 0;
- while ((res = PQgetResult(st->con)) != NULL)
+ res = PQgetResult(st->con);
+
+ while (res != NULL)
{
+ /* look now at the next result to know whether it is the last */
+ PGresult *next_res = PQgetResult(st->con);
+ bool is_last = (next_res == NULL);
+
switch (PQresultStatus(res))
{
case PGRES_COMMAND_OK: /* non-SELECT commands */
case PGRES_EMPTY_QUERY: /* may be used for testing no-op overhead */
- if (varprefix && varprefix[qrynum] != NULL)
+ if (is_last && varprefix != NULL)
{
fprintf(stderr,
"client %d script %d command %d query %d: expected one row, got %d\n",
@@ -2876,7 +2874,7 @@ readCommandResponse(CState *st, char **varprefix)
break;
case PGRES_TUPLES_OK:
- if (varprefix && varprefix[qrynum] != NULL)
+ if (is_last && varprefix != NULL)
{
if (PQntuples(res) != 1)
{
@@ -2895,9 +2893,9 @@ readCommandResponse(CState *st, char **varprefix)
char *varname = PQfname(res, fld);
/* allocate varname only if necessary, freed below */
- if (*varprefix[qrynum] != '\0')
+ if (*varprefix != '\0')
varname =
- psprintf("%s%s", varprefix[qrynum], varname);
+ psprintf("%s%s", varprefix, varname);
/* store result as a string */
if (!putVariable(st, "gset", varname,
@@ -2914,7 +2912,7 @@ readCommandResponse(CState *st, char **varprefix)
return false;
}
- if (*varprefix[qrynum] != '\0')
+ if (*varprefix != '\0')
pg_free(varname);
}
}
@@ -2935,6 +2933,7 @@ readCommandResponse(CState *st, char **varprefix)
PQclear(res);
qrynum++;
+ res = next_res;
}
if (qrynum == 0)
@@ -4248,7 +4247,7 @@ skip_sql_comments(char *sql_command)
* struct.
*/
static Command *
-create_sql_command(PQExpBuffer buf, const char *source, int numqueries)
+create_sql_command(PQExpBuffer buf, const char *source)
{
Command *my_command;
char *p = skip_sql_comments(buf->data);
@@ -4265,9 +4264,7 @@ create_sql_command(PQExpBuffer buf, const char *source, int numqueries)
my_command->meta = META_NONE;
my_command->argc = 0;
memset(my_command->argv, 0, sizeof(my_command->argv));
- my_command->nqueries = numqueries;
my_command->varprefix = NULL; /* allocated later, if needed */
- my_command->varprefix_max = 0;
my_command->expr = NULL;
initSimpleStats(&my_command->stats);
@@ -4284,39 +4281,14 @@ free_command(Command *command)
for (int i = 0; i < command->argc; i++)
pg_free(command->argv[i]);
if (command->varprefix)
- {
- for (int i = 0; i < command->varprefix_max; i++)
- if (command->varprefix[i] &&
- command->varprefix[i][0] != '\0') /* see ParseScript */
- pg_free(command->varprefix[i]);
pg_free(command->varprefix);
- }
/*
* It should also free expr recursively, but this is currently not needed
- * as only \{g,c}set commands (which do not have an expression) are freed.
+ * as only gset commands (which do not have an expression) are freed.
*/
pg_free(command);
}
-/*
- * append "more" text to current compound command which had been interrupted
- * by \cset.
- */
-static void
-append_sql_command(Command *my_command, char *more, int numqueries)
-{
- Assert(my_command->type == SQL_COMMAND && my_command->lines.len > 0);
-
- more = skip_sql_comments(more);
- if (more == NULL)
- return;
-
- /* append command text, embedding a ';' in place of the \cset */
- appendPQExpBuffer(&my_command->lines, ";\n%s", more);
-
- my_command->nqueries += numqueries;
-}
-
/*
* Once an SQL command is fully parsed, possibly by accumulating several
* parts, complete other fields of the Command structure.
@@ -4350,35 +4322,6 @@ postprocess_sql_command(Command *my_command)
}
}
-/*
- * Determine the command's varprefix size needed and allocate memory for it
- */
-static void
-allocate_command_varprefix(Command *cmd, int totalqueries)
-{
- int new_max;
-
- /* sufficient space already allocated? */
- if (totalqueries <= cmd->varprefix_max)
- return;
-
- /* determine the new array size */
- new_max = Max(cmd->varprefix_max, 2);
- while (new_max < totalqueries)
- new_max *= 2;
-
- /* enlarge the array, zero-initializing the allocated space */
- if (cmd->varprefix == NULL)
- cmd->varprefix = pg_malloc0(sizeof(char *) * new_max);
- else
- {
- cmd->varprefix = pg_realloc(cmd->varprefix, sizeof(char *) * new_max);
- memset(cmd->varprefix + cmd->varprefix_max, 0,
- sizeof(char *) * (new_max - cmd->varprefix_max));
- }
- cmd->varprefix_max = new_max;
-}
-
/*
* Parse a backslash command; return a Command struct, or NULL if comment
*
@@ -4549,7 +4492,7 @@ process_backslash_command(PsqlScanState sstate, const char *source)
syntax_error(source, lineno, my_command->first_line, my_command->argv[0],
"unexpected argument", NULL, -1);
}
- else if (my_command->meta == META_CSET || my_command->meta == META_GSET)
+ else if (my_command->meta == META_GSET)
{
if (my_command->argc > 2)
syntax_error(source, lineno, my_command->first_line, my_command->argv[0],
@@ -4637,7 +4580,6 @@ ParseScript(const char *script, const char *desc, int weight)
PQExpBufferData line_buf;
int alloc_num;
int index;
- bool saw_cset = false;
int lineno;
int start_offset;
@@ -4674,31 +4616,18 @@ ParseScript(const char *script, const char *desc, int weight)
PsqlScanResult sr;
promptStatus_t prompt;
Command *command = NULL;
- int semicolons;
resetPQExpBuffer(&line_buf);
lineno = expr_scanner_get_lineno(sstate, start_offset);
sr = psql_scan(sstate, &line_buf, &prompt);
- semicolons = psql_scan_get_escaped_semicolons(sstate);
+ /* If we collected a new SQL command, process that */
+ command = create_sql_command(&line_buf, desc);
- if (saw_cset)
- {
- /* the previous multi-line command ended with \cset */
- append_sql_command(ps.commands[index - 1], line_buf.data,
- semicolons + 1);
- saw_cset = false;
- }
- else
- {
- /* If we collected a new SQL command, process that */
- command = create_sql_command(&line_buf, desc, semicolons + 1);
-
- /* store new command */
- if (command)
- ps.commands[index++] = command;
- }
+ /* store new command */
+ if (command)
+ ps.commands[index++] = command;
/* If we reached a backslash, process that */
if (sr == PSCAN_BACKSLASH)
@@ -4708,56 +4637,39 @@ ParseScript(const char *script, const char *desc, int weight)
if (command)
{
/*
- * If this is gset/cset, merge into the preceding command. (We
+ * If this is gset, merge into the preceding command. (We
* don't use a command slot in this case).
*/
- if (command->meta == META_CSET ||
- command->meta == META_GSET)
+ if (command->meta == META_GSET)
{
- int cindex;
Command *cmd;
- /*
- * If \cset is seen, set flag to leave the command pending
- * for the next iteration to process.
- */
- saw_cset = command->meta == META_CSET;
-
if (index == 0)
syntax_error(desc, lineno, NULL, NULL,
- "\\gset/cset cannot start a script",
+ "\\gset cannot start a script",
NULL, -1);
cmd = ps.commands[index - 1];
if (cmd->type != SQL_COMMAND)
syntax_error(desc, lineno, NULL, NULL,
- "\\gset/cset must follow a SQL command",
+ "\\gset must follow a SQL command",
cmd->first_line, -1);
- /* this {g,c}set applies to the previous query */
- cindex = cmd->nqueries - 1;
-
/*
- * now that we know there's a {g,c}set in this command,
- * allocate space for the variable name prefix array.
- */
- allocate_command_varprefix(cmd, cmd->nqueries);
-
- /*
- * Don't allow the previous command be a gset/cset; that
+ * Don't allow the previous command be a gset; that
* would make no sense.
*/
- if (cmd->varprefix[cindex] != NULL)
+ if (cmd->varprefix != NULL)
syntax_error(desc, lineno, NULL, NULL,
- "\\gset/cset cannot follow one another",
+ "\\gset cannot follow one another",
NULL, -1);
/* get variable prefix */
if (command->argc <= 1 || command->argv[1][0] == '\0')
- cmd->varprefix[cindex] = ""; /* avoid strdup */
+ cmd->varprefix = pg_strdup("");
else
- cmd->varprefix[cindex] = pg_strdup(command->argv[1]);
+ cmd->varprefix = pg_strdup(command->argv[1]);
/* cleanup unused command */
free_command(command);
diff --git a/src/bin/pgbench/t/001_pgbench_with_server.pl b/src/bin/pgbench/t/001_pgbench_with_server.pl
index 45888dc12e..e7e0042790 100644
--- a/src/bin/pgbench/t/001_pgbench_with_server.pl
+++ b/src/bin/pgbench/t/001_pgbench_with_server.pl
@@ -538,22 +538,18 @@ pgbench(
}
});
-# working \gset and \cset
+# working \gset
pgbench(
'-t 1', 0,
- [ qr{type: .*/001_pgbench_gset_and_cset}, qr{processed: 1/1} ],
+ [ qr{type: .*/001_pgbench_gset}, qr{processed: 1/1} ],
[ qr{command=3.: int 0\b},
qr{command=5.: int 1\b},
qr{command=6.: int 2\b},
qr{command=8.: int 3\b},
- qr{command=9.: int 4\b},
- qr{command=10.: int 5\b},
- qr{command=12.: int 6\b},
- qr{command=13.: int 7\b},
- qr{command=14.: int 8\b},
- qr{command=16.: int 9\b} ],
- 'pgbench gset and cset commands',
- { '001_pgbench_gset_and_cset' => q{-- test gset and cset
+ qr{command=10.: int 4\b},
+ qr{command=12.: int 5\b} ],
+ 'pgbench gset command',
+ { '001_pgbench_gset' => q{-- test gset
-- no columns
SELECT \gset
-- one value
@@ -563,21 +559,15 @@ SELECT 0 AS i0 \gset
SELECT 1 AS i1, 2 AS i2 \gset
\set i debug(:i1)
\set i debug(:i2)
--- cset & gset to follow
-SELECT :i2 + 1 AS i3, :i2 * :i2 AS i4 \cset
- SELECT 5 AS i5 \gset
-\set i debug(:i3)
-\set i debug(:i4)
-\set i debug(:i5)
-- with prefix
-SELECT 6 AS i6, 7 AS i7 \cset x_
- SELECT 8 AS i8 \gset y_
-\set i debug(:x_i6)
-\set i debug(:x_i7)
-\set i debug(:y_i8)
+SELECT 3 AS i3 \gset x_
+\set i debug(:x_i3)
-- overwrite existing variable
-SELECT 0 AS i9, 9 AS i9 \gset
-\set i debug(:i9)
+SELECT 0 AS i4, 4 AS i4 \gset
+\set i debug(:i4)
+-- work on the last SQL command under \;
+\; \; SELECT 0 AS i5 \; SELECT 5 AS i5 \; \; \gset
+\set i debug(:i5)
} });
# trigger many expression errors
@@ -772,20 +762,17 @@ SELECT LEAST(}.join(', ', (':i') x 256).q{)}
[ 'bad boolean', 2,
[qr{malformed variable.*trueXXX}], q{\set b :badtrue or true} ],
- # GSET & CSET
+ # GSET
[ 'gset no row', 2,
[qr{expected one row, got 0\b}], q{SELECT WHERE FALSE \gset} ],
- [ 'cset no row', 2,
- [qr{expected one row, got 0\b}], q{SELECT WHERE FALSE \cset
-SELECT 1 AS i\gset}, 1 ],
- [ 'gset alone', 1, [qr{gset/cset cannot start a script}], q{\gset} ],
+ [ 'gset alone', 1, [qr{gset cannot start a script}], q{\gset} ],
[ 'gset no SQL', 1,
- [qr{gset/cset must follow a SQL command}], q{\set i +1
+ [qr{gset must follow a SQL command}], q{\set i +1
\gset} ],
[ 'gset too many arguments', 1,
[qr{too many arguments}], q{SELECT 1 \gset a b} ],
[ 'gset after gset', 1,
- [qr{gset/cset cannot follow one another}], q{SELECT 1 AS i \gset
+ [qr{gset cannot follow one another}], q{SELECT 1 AS i \gset
\gset} ],
[ 'gset non SELECT', 2,
[qr{expected one row, got 0}],
diff --git a/src/fe_utils/psqlscan.l b/src/fe_utils/psqlscan.l
index 321744cddb..b31527b94f 100644
--- a/src/fe_utils/psqlscan.l
+++ b/src/fe_utils/psqlscan.l
@@ -693,15 +693,8 @@ other .
* substitution. We want these before {self}, also.
*/
-"\\"; {
- /* Count semicolons in compound commands */
- cur_state->escaped_semicolons++;
- /* Force a semicolon into the query buffer */
- psqlscan_emit(cur_state, yytext + 1, 1);
- }
-
-"\\": {
- /* Force a colon into the query buffer */
+"\\"[;:] {
+ /* Force a semi-colon or colon into the query buffer */
psqlscan_emit(cur_state, yytext + 1, 1);
}
@@ -1072,9 +1065,6 @@ psql_scan(PsqlScanState state,
/* Set current output target */
state->output_buf = query_buf;
- /* Reset number of escaped semicolons seen */
- state->escaped_semicolons = 0;
-
/* Set input source */
if (state->buffer_stack != NULL)
yy_switch_to_buffer(state->buffer_stack->buf, state->scanner);
@@ -1218,16 +1208,6 @@ psql_scan_reset(PsqlScanState state)
state->dolqstart = NULL;
}
-/*
- * Return the number of escaped semicolons in the lexed string seen by the
- * previous psql_scan call.
- */
-int
-psql_scan_get_escaped_semicolons(PsqlScanState state)
-{
- return state->escaped_semicolons;
-}
-
/*
* Reselect this lexer (psqlscan.l) after using another one.
*
diff --git a/src/include/fe_utils/psqlscan.h b/src/include/fe_utils/psqlscan.h
index d6fef9ff77..1cf5b2e7fa 100644
--- a/src/include/fe_utils/psqlscan.h
+++ b/src/include/fe_utils/psqlscan.h
@@ -90,8 +90,6 @@ extern PsqlScanResult psql_scan(PsqlScanState state,
extern void psql_scan_reset(PsqlScanState state);
-extern int psql_scan_get_escaped_semicolons(PsqlScanState state);
-
extern void psql_scan_reselect_sql_lexer(PsqlScanState state);
extern bool psql_scan_in_quote(PsqlScanState state);
diff --git a/src/include/fe_utils/psqlscan_int.h b/src/include/fe_utils/psqlscan_int.h
index 752cc9406a..42a738f422 100644
--- a/src/include/fe_utils/psqlscan_int.h
+++ b/src/include/fe_utils/psqlscan_int.h
@@ -112,7 +112,6 @@ typedef struct PsqlScanStateData
int start_state; /* yylex's starting/finishing state */
int paren_depth; /* depth of nesting in parentheses */
int xcdepth; /* depth of nesting in slash-star comments */
- int escaped_semicolons; /* number of embedded (\;) semicolons */
char *dolqstart; /* current $foo$ quote start string */
/*
