On 05/04/2019 12:23, Peter Eisentraut wrote:
On 2019-03-29 15:55, Alexey Bashtanov wrote:
ERROR: value "62812" is out of range for type smallint
STATEMENT: SELECT abalance FROM pgbench_accounts WHERE aid = $1;
(In this case the error message contains the parameter value, so it's
not a very practical case, but it should work, it seems.)
I guess this error occurred /while/ binding, so the parameters probably
weren't yet all bound by the time of error reporting.
That's why the error message came without parameters.
I see. But I think that could be fixed. Change exec_bind_message() to
loop over the parameters twice: once to save them away, once to actually
process them. I think the case of a faulty input value is probably very
common, so it would be confusing if that didn't work.
I understand this may sound lazy of me, however let me take this risk
and try to explain why I think logging them here in the same fashion
would be inconsistent.
The original feature is intended to log textual representations of
the bind parameter values, whereas the problem suggested to be solved
together with it is verbose logging of the part of the bind message that
failed to get converted to a Datum.
These are equivalent only under the following conditions:
1) the rest of the message was correctly formatted, so we can extract
something for each of the parameter values
2) the values have been passed in text mode
(all of them, not only the one failed to process)
3) the values have been passed in the server encoding
I think it would be a bit of inconsistent to log the parts of the message
only when we are lucky to satisfy the 3 conditions above.
If we are to log bind parameters message parsing and processing problems
more verbosely, what do you think of rather wrapping calls to
OidInputFunctionCall, OidReceiveFunctionCall and pg_client_to_server
into PG_TRY blocks and logging their arguments individually?
In case it doesn't work for any reason, I have an alternative idea on
how to log half-processed parameters.
Instead of hasTextValues store the number of parameters having
their textual representations successfully saved.
This way we will be able, in case of text mode,
save the original value and increment the counter
before the call to OidInputFunctionCall. When logging and not having values
for some parameters, we can print an ellipsis in the log to indicate there's
some more of them missing.
I think this patch needs some tests. Manually testing it is cumbersome,
and as we are seeing now, it is not quite clear which cases it is
supposed to cover. There are also additional cases for binary
parameters, and there are additions to the CSV output format. We need
tests for all that so the behavior explains itself and doesn't have to
be rediscovered every time someone wants to look at this again.
I have added a section into src/test/examples/testlibpq3.c,
please see attached.
As far as I could see these tests never run on "make check" or "make
installcheck",
hence the README change. Please correct me if I'm wrong.
I also failed to find an automatic way to test what actually gets logged
to the server log, at least not in the installcheck case.
I would appreciate if you had any suggestions about it.
Best regards,
Alex
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 75f9471..437dc44 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -6418,6 +6418,23 @@ log_line_prefix = '%m [%p] %q%u@%d/%a '
</listitem>
</varlistentry>
+ <varlistentry id="guc-log-parameters-on-error" xreflabel="log_parameters_on_error">
+ <term><varname>log_parameters_on_error</varname> (<type>boolean</type>)
+ <indexterm>
+ <primary><varname>log_parameters_on_error</varname> configuration parameter</primary>
+ </indexterm>
+ </term>
+ <listitem>
+ <para>
+ Controls whether the statement is logged with bind parameter values.
+ It adds some overhead, as postgres will cache textual
+ representations of parameter values in memory for all statements,
+ even if they eventually do not get logged. The default is
+ <literal>off</literal>. Only superusers can change this setting.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry id="guc-log-statement" xreflabel="log_statement">
<term><varname>log_statement</varname> (<type>enum</type>)
<indexterm>
diff --git a/src/backend/nodes/params.c b/src/backend/nodes/params.c
index f5d5613..5e5ccf1 100644
--- a/src/backend/nodes/params.c
+++ b/src/backend/nodes/params.c
@@ -45,6 +45,7 @@ makeParamList(int numParams)
retval->parserSetup = NULL;
retval->parserSetupArg = NULL;
retval->numParams = numParams;
+ retval->hasTextValues = false;
return retval;
}
@@ -58,6 +59,10 @@ makeParamList(int numParams)
* set of parameter values. If dynamic parameter hooks are present, we
* intentionally do not copy them into the result. Rather, we forcibly
* instantiate all available parameter values and copy the datum values.
+ *
+ * Since this function is never used for copying parameters into a top portal,
+ * we don't copy textual representations. Neither we set the hasTextValues
+ * flag, so noone will access them.
*/
ParamListInfo
copyParamList(ParamListInfo from)
diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c
index 44a59e1..3559163 100644
--- a/src/backend/tcop/postgres.c
+++ b/src/backend/tcop/postgres.c
@@ -86,6 +86,12 @@
*/
const char *debug_query_string; /* client-supplied query string */
+/*
+ * The top-level portal that the client is immediately working with:
+ * creating, binding, executing, or all at one using simple protocol
+ */
+Portal current_top_portal = NULL;
+
/* Note: whereToSendOutput is initialized for the bootstrap/standalone case */
CommandDest whereToSendOutput = DestDebug;
@@ -1694,6 +1700,9 @@ exec_bind_message(StringInfo input_message)
else
portal = CreatePortal(portal_name, false, false);
+ Assert(current_top_portal == NULL);
+ current_top_portal = portal;
+
/*
* Prepare to copy stuff into the portal's memory context. We do all this
* copying first, because it could possibly fail (out-of-memory) and we
@@ -1731,6 +1740,9 @@ exec_bind_message(StringInfo input_message)
*/
if (numParams > 0)
{
+ /* GUC value can change, so we remember its state to be consistent */
+ bool need_text_values = log_parameters_on_error;
+
params = makeParamList(numParams);
for (int paramno = 0; paramno < numParams; paramno++)
@@ -1798,9 +1810,31 @@ exec_bind_message(StringInfo input_message)
pval = OidInputFunctionCall(typinput, pstring, typioparam, -1);
- /* Free result of encoding conversion, if any */
- if (pstring && pstring != pbuf.data)
- pfree(pstring);
+ if (pstring)
+ {
+ if (need_text_values)
+ {
+ if (pstring == pbuf.data)
+ {
+ /*
+ * Copy textual representation to portal context.
+ */
+ params->params[paramno].textValue =
+ pstrdup(pstring);
+ }
+ else
+ {
+ /* Reuse the result of encoding conversion for it */
+ params->params[paramno].textValue = pstring;
+ }
+ }
+ else
+ {
+ /* Free result of encoding conversion */
+ if (pstring != pbuf.data)
+ pfree(pstring);
+ }
+ }
}
else if (pformat == 1) /* binary mode */
{
@@ -1826,6 +1860,22 @@ exec_bind_message(StringInfo input_message)
(errcode(ERRCODE_INVALID_BINARY_REPRESENTATION),
errmsg("incorrect binary data format in bind parameter %d",
paramno + 1)));
+
+ /*
+ * Compute textual representation for further logging. We waste
+ * some time and memory here, maybe one day we could skip
+ * certain types like built-in primitives, which are safe to get
+ * it calculated later in an aborted xact.
+ */
+ if (!isNull && need_text_values)
+ {
+ Oid typoutput;
+ bool typisvarlena;
+
+ getTypeOutputInfo(ptype, &typoutput, &typisvarlena);
+ params->params[paramno].textValue =
+ OidOutputFunctionCall(typoutput, pval);
+ }
}
else
{
@@ -1850,10 +1900,22 @@ exec_bind_message(StringInfo input_message)
params->params[paramno].pflags = PARAM_FLAG_CONST;
params->params[paramno].ptype = ptype;
}
+
+ /*
+ * only now we can safely set it, as we have textValue populated
+ * for all non-null parameters
+ */
+ params->hasTextValues = need_text_values;
}
else
params = NULL;
+ /*
+ * Set portal parameters early for them to get logged if an error happens
+ * on planning stage
+ */
+ portal->portalParams = params;
+
/* Done storing stuff in portal's context */
MemoryContextSwitchTo(oldContext);
@@ -1934,6 +1996,7 @@ exec_bind_message(StringInfo input_message)
if (save_log_statement_stats)
ShowUsage("BIND MESSAGE STATISTICS");
+ current_top_portal = NULL;
debug_query_string = NULL;
}
@@ -1969,7 +2032,6 @@ exec_execute_message(const char *portal_name, long max_rows)
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_CURSOR),
errmsg("portal \"%s\" does not exist", portal_name)));
-
/*
* If the original query was a null string, just return
* EmptyQueryResponse.
@@ -1984,32 +2046,49 @@ exec_execute_message(const char *portal_name, long max_rows)
/* Does the portal contain a transaction command? */
is_xact_command = IsTransactionStmtList(portal->stmts);
- /*
- * We must copy the sourceText and prepStmtName into MessageContext in
- * case the portal is destroyed during finish_xact_command. Can avoid the
- * copy if it's not an xact command, though.
- */
if (is_xact_command)
{
+ /*
+ * We must copy the sourceText and prepStmtName into MessageContext in
+ * case the portal is destroyed during finish_xact_command.
+ */
sourceText = pstrdup(portal->sourceText);
if (portal->prepStmtName)
prepStmtName = pstrdup(portal->prepStmtName);
else
prepStmtName = "<unnamed>";
-
/*
* An xact command shouldn't have any parameters, which is a good
* thing because they wouldn't be around after finish_xact_command.
*/
portalParams = NULL;
+
+ /*
+ * We don't set current top portal for xact cmds, as
+ * 1) the portal may be destroyed earlier than the error happens
+ * 2) it anyway has no parameters in it to log
+ */
+ Assert(current_top_portal == NULL);
}
else
{
+ /*
+ * The portal will remain there until we leave the function, so it's
+ * safe avoid copying and just to refer to the data in its memory
+ * context instead
+ */
sourceText = portal->sourceText;
if (portal->prepStmtName)
prepStmtName = portal->prepStmtName;
else
prepStmtName = "<unnamed>";
+
+ /*
+ * For non-xact commands, we remember the current portal and its bind
+ * parameters for further use in logging
+ */
+ Assert(current_top_portal == NULL);
+ current_top_portal = portal;
portalParams = portal->portalParams;
}
@@ -2158,6 +2237,7 @@ exec_execute_message(const char *portal_name, long max_rows)
if (save_log_statement_stats)
ShowUsage("EXECUTE MESSAGE STATISTICS");
+ current_top_portal = NULL;
debug_query_string = NULL;
}
@@ -2299,61 +2379,18 @@ errdetail_execute(List *raw_parsetree_list)
static int
errdetail_params(ParamListInfo params)
{
- /* We mustn't call user-defined I/O functions when in an aborted xact */
- if (params && params->numParams > 0 && !IsAbortedTransactionBlockState())
- {
- StringInfoData param_str;
- MemoryContext oldcontext;
-
- /* This code doesn't support dynamic param lists */
- Assert(params->paramFetch == NULL);
-
- /* Make sure any trash is generated in MessageContext */
- oldcontext = MemoryContextSwitchTo(MessageContext);
-
- initStringInfo(¶m_str);
-
- for (int paramno = 0; paramno < params->numParams; paramno++)
- {
- ParamExternData *prm = ¶ms->params[paramno];
- Oid typoutput;
- bool typisvarlena;
- char *pstring;
- char *p;
-
- appendStringInfo(¶m_str, "%s$%d = ",
- paramno > 0 ? ", " : "",
- paramno + 1);
-
- if (prm->isnull || !OidIsValid(prm->ptype))
- {
- appendStringInfoString(¶m_str, "NULL");
- continue;
- }
-
- getTypeOutputInfo(prm->ptype, &typoutput, &typisvarlena);
-
- pstring = OidOutputFunctionCall(typoutput, prm->value);
-
- appendStringInfoCharMacro(¶m_str, '\'');
- for (p = pstring; *p; p++)
- {
- if (*p == '\'') /* double single quotes */
- appendStringInfoCharMacro(¶m_str, *p);
- appendStringInfoCharMacro(¶m_str, *p);
- }
- appendStringInfoCharMacro(¶m_str, '\'');
-
- pfree(pstring);
- }
-
- errdetail("parameters: %s", param_str.data);
+ /* Make sure any trash is generated in MessageContext */
+ MemoryContext oldcontext = MemoryContextSwitchTo(MessageContext);
+ char *params_message = get_portal_bind_parameters(params);
- pfree(param_str.data);
-
- MemoryContextSwitchTo(oldcontext);
+ if (params_message)
+ {
+ errdetail("parameters: %s", params_message);
+ pfree(params_message);
}
+ MemoryContextSwitchTo(oldcontext);
+
return 0;
}
@@ -2671,6 +2708,87 @@ drop_unnamed_stmt(void)
}
}
+/*
+ * get_portal_bind_parameters
+ * Get the string containing parameters data, is used for logging.
+ *
+ * Can return NULL if there are no parameters in the portal
+ * or the portal is not valid, or the text representations of the parameters are
+ * not available. If returning a non-NULL value, it allocates memory
+ * for the returned string in the current context, and it's the caller's
+ * responsibility to pfree() it if needed.
+ */
+char *
+get_portal_bind_parameters(ParamListInfo params)
+{
+ StringInfoData param_str;
+
+ /* No parameters to format */
+ if (!params || params->numParams == 0)
+ return NULL;
+
+ /*
+ * We either need textual representation of parameters pre-calcualted,
+ * or call potentially user-defined I/O functions to convert internal
+ * representation into text, which cannot be done in an aborted xact
+ */
+ if (!params->hasTextValues && IsAbortedTransactionBlockState())
+ return NULL;
+
+ initStringInfo(¶m_str);
+
+ /* This code doesn't support dynamic param lists */
+ Assert(params->paramFetch == NULL);
+
+ for (int paramno = 0; paramno < params->numParams; paramno++)
+ {
+ ParamExternData *prm = ¶ms->params[paramno];
+ char *pstring;
+ char *p;
+
+ appendStringInfo(¶m_str, "%s$%d = ",
+ paramno > 0 ? ", " : "",
+ paramno + 1);
+
+ if (prm->isnull)
+ {
+ appendStringInfoString(¶m_str, "NULL");
+ continue;
+ }
+
+ if (params->hasTextValues)
+ pstring = prm->textValue;
+ else
+ {
+ Oid typoutput;
+ bool typisvarlena;
+
+ if (!OidIsValid(prm->ptype))
+ {
+ appendStringInfoString(¶m_str, "UNKNOWN TYPE");
+ continue;
+ }
+
+ getTypeOutputInfo(prm->ptype, &typoutput, &typisvarlena);
+ pstring = OidOutputFunctionCall(typoutput, prm->value);
+ }
+
+ appendStringInfoCharMacro(¶m_str, '\'');
+ for (p = pstring; *p; p++)
+ {
+ if (*p == '\'') /* double single quotes */
+ appendStringInfoCharMacro(¶m_str, *p);
+ appendStringInfoCharMacro(¶m_str, *p);
+ }
+ appendStringInfoCharMacro(¶m_str, '\'');
+
+ if (!params->hasTextValues)
+ pfree(pstring);
+ }
+
+ return param_str.data;
+}
+
/* --------------------------------
* signal handler routines used in PostgresMain()
@@ -4024,10 +4142,11 @@ PostgresMain(int argc, char *argv[],
EmitErrorReport();
/*
- * Make sure debug_query_string gets reset before we possibly clobber
- * the storage it points at.
+ * Make sure these get reset before we possibly clobber
+ * the storages they point at.
*/
debug_query_string = NULL;
+ current_top_portal = NULL;
/*
* Abort the current transaction in order to recover.
diff --git a/src/backend/utils/error/elog.c b/src/backend/utils/error/elog.c
index 8b4720e..e18d9e5 100644
--- a/src/backend/utils/error/elog.c
+++ b/src/backend/utils/error/elog.c
@@ -76,6 +76,7 @@
#include "tcop/tcopprot.h"
#include "utils/guc.h"
#include "utils/memutils.h"
+#include "utils/portal.h"
#include "utils/ps_status.h"
@@ -344,6 +345,7 @@ errstart(int elevel, const char *filename, int lineno,
{
error_context_stack = NULL;
debug_query_string = NULL;
+ current_top_portal = NULL;
}
}
if (++errordata_stack_depth >= ERRORDATA_STACK_SIZE)
@@ -2788,6 +2790,18 @@ write_csvlog(ErrorData *edata)
if (print_stmt && edata->cursorpos > 0)
appendStringInfo(&buf, "%d", edata->cursorpos);
appendStringInfoChar(&buf, ',');
+ if (print_stmt && log_parameters_on_error
+ && PortalIsValid(current_top_portal))
+ {
+ char *param_values =
+ get_portal_bind_parameters(current_top_portal->portalParams);
+ if (param_values != NULL)
+ {
+ appendCSVLiteral(&buf, param_values);
+ pfree(param_values);
+ }
+ }
+ appendStringInfoChar(&buf, ',');
/* file error location */
if (Log_error_verbosity >= PGERROR_VERBOSE)
@@ -2944,6 +2958,18 @@ send_message_to_server_log(ErrorData *edata)
appendStringInfoString(&buf, _("STATEMENT: "));
append_with_tabs(&buf, debug_query_string);
appendStringInfoChar(&buf, '\n');
+
+ if (log_parameters_on_error && PortalIsValid(current_top_portal))
+ {
+ char *param_values =
+ get_portal_bind_parameters(current_top_portal->portalParams);
+ if (param_values != NULL)
+ {
+ log_line_prefix(&buf, edata);
+ appendStringInfo(&buf, _("PARAMETERS: %s\n"), param_values);
+ pfree(param_values);
+ }
+ }
}
#ifdef HAVE_SYSLOG
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index f7f726b..9034303 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -483,6 +483,7 @@ extern const struct config_enum_entry dynamic_shared_memory_options[];
* GUC option variables that are exported from this module
*/
bool log_duration = false;
+bool log_parameters_on_error = false;
bool Debug_print_plan = false;
bool Debug_print_parse = false;
bool Debug_print_rewritten = false;
@@ -1296,6 +1297,15 @@ static struct config_bool ConfigureNamesBool[] =
NULL, NULL, NULL
},
{
+ {"log_parameters_on_error", PGC_SUSET, LOGGING_WHAT,
+ gettext_noop("Logs bind parameters of the logged statements where possible."),
+ NULL
+ },
+ &log_parameters_on_error,
+ false,
+ NULL, NULL, NULL
+ },
+ {
{"debug_print_parse", PGC_USERSET, LOGGING_WHAT,
gettext_noop("Logs each query's parse tree."),
NULL
diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
index 77bb7c2..b21ca36 100644
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -536,6 +536,7 @@
# e.g. '<%u%%%d> '
#log_lock_waits = off # log lock waits >= deadlock_timeout
#log_statement = 'none' # none, ddl, mod, all
+#log_parameters_on_error = off # on error log statements with bind parameters
#log_replication_commands = off
#log_temp_files = -1 # log temporary files equal or larger
# than the specified size in kilobytes;
diff --git a/src/include/nodes/params.h b/src/include/nodes/params.h
index fd90466..316d3a2 100644
--- a/src/include/nodes/params.h
+++ b/src/include/nodes/params.h
@@ -93,6 +93,7 @@ typedef struct ParamExternData
bool isnull; /* is it NULL? */
uint16 pflags; /* flag bits, see above */
Oid ptype; /* parameter's datatype, or 0 */
+ char *textValue; /* textual representation for debug purposes */
} ParamExternData;
typedef struct ParamListInfoData *ParamListInfo;
@@ -116,6 +117,8 @@ typedef struct ParamListInfoData
ParserSetupHook parserSetup; /* parser setup hook */
void *parserSetupArg;
int numParams; /* nominal/maximum # of Params represented */
+ bool hasTextValues; /* whether textValue for all non-null
+ params is populated */
/*
* params[] may be of length zero if paramFetch is supplied; otherwise it
diff --git a/src/include/tcop/tcopprot.h b/src/include/tcop/tcopprot.h
index b367838..2cfa2ac 100644
--- a/src/include/tcop/tcopprot.h
+++ b/src/include/tcop/tcopprot.h
@@ -24,6 +24,7 @@
#include "nodes/plannodes.h"
#include "storage/procsignal.h"
#include "utils/guc.h"
+#include "utils/portal.h"
#include "utils/queryenvironment.h"
@@ -32,6 +33,8 @@
extern CommandDest whereToSendOutput;
extern PGDLLIMPORT const char *debug_query_string;
+extern PGDLLIMPORT Portal current_top_portal;
+
extern int max_stack_depth;
extern int PostAuthDelay;
@@ -83,6 +86,7 @@ extern long get_stack_depth_rlimit(void);
extern void ResetUsage(void);
extern void ShowUsage(const char *title);
extern int check_log_duration(char *msec_str, bool was_logged);
+extern char *get_portal_bind_parameters(ParamListInfo params);
extern void set_debug_options(int debug_flag,
GucContext context, GucSource source);
extern bool set_plan_disabling_options(const char *arg,
diff --git a/src/include/utils/guc.h b/src/include/utils/guc.h
index 6c41eda..e5f8d39 100644
--- a/src/include/utils/guc.h
+++ b/src/include/utils/guc.h
@@ -234,6 +234,7 @@ typedef enum
/* GUC vars that are actually declared in guc.c, rather than elsewhere */
extern bool log_duration;
+extern bool log_parameters_on_error;
extern bool Debug_print_plan;
extern bool Debug_print_parse;
extern bool Debug_print_rewritten;
diff --git a/src/test/README b/src/test/README
index b5ccfc0..22e624d 100644
--- a/src/test/README
+++ b/src/test/README
@@ -12,8 +12,7 @@ authentication/
Tests for authentication
examples/
- Demonstration programs for libpq that double as regression tests via
- "make check"
+ Demonstration programs for libpq that double as regression tests
isolation/
Tests for concurrent behavior at the SQL level
diff --git a/src/test/examples/testlibpq3.c b/src/test/examples/testlibpq3.c
index c3b524c..3b76d66 100644
--- a/src/test/examples/testlibpq3.c
+++ b/src/test/examples/testlibpq3.c
@@ -42,7 +42,6 @@
#include <netinet/in.h>
#include <arpa/inet.h>
-
static void
exit_nicely(PGconn *conn)
{
@@ -116,9 +115,9 @@ main(int argc, char **argv)
const char *conninfo;
PGconn *conn;
PGresult *res;
- const char *paramValues[1];
- int paramLengths[1];
- int paramFormats[1];
+ const char *paramValues[2];
+ int paramLengths[2];
+ int paramFormats[2];
uint32_t binaryIntVal;
/*
@@ -224,6 +223,52 @@ main(int argc, char **argv)
PQclear(res);
+ /*
+ * In the third example we transmit parameters in different forms, make
+ * a statement fail and check how logging parameters on error works.
+ */
+ /* Set always-secure search path, so malicious users can't take control. */
+
+ res = PQexec(conn, "SET log_parameters_on_error = on");
+ if (PQresultStatus(res) != PGRES_COMMAND_OK)
+ {
+ fprintf(stderr, "SET failed: %s", PQerrorMessage(conn));
+ PQclear(res);
+ exit_nicely(conn);
+ }
+ PQclear(res);
+
+ paramValues[0] = (char *) &binaryIntVal;
+ paramLengths[0] = sizeof(binaryIntVal);
+ paramFormats[0] = 1; /* binary */
+ paramValues[1] = "2";
+ paramLengths[1] = strlen(paramValues[1]) + 1;
+ paramFormats[1] = 0; /* text */
+ res = PQexecParams(conn,
+ /*
+ * always divide by zero,
+ * but deduce it only when executing
+ */
+ "SELECT 1 / (random() / 2)::int + $1::int + $2::int",
+ 2, /* two params */
+ NULL, /* let the backend deduce param type */
+ paramValues,
+ paramLengths,
+ paramFormats,
+ 1); /* ask for binary results */
+
+ if (PQresultStatus(res) != PGRES_FATAL_ERROR)
+ {
+ fprintf(stderr, "SELECT succeeded but was supposed to fail");
+ PQclear(res);
+ exit_nicely(conn);
+ }
+ PQclear(res);
+ printf("Division by zero expected, got an error message from server: %s"
+ "Please make sure it has been logged "
+ "with bind parameters in server log\n",
+ PQerrorMessage(conn));
+
/* close the connection to the database and cleanup */
PQfinish(conn);
