diff options
Diffstat (limited to 'contrib/pg_stat_statements/pg_stat_statements.c')
| -rw-r--r-- | contrib/pg_stat_statements/pg_stat_statements.c | 40 |
1 files changed, 30 insertions, 10 deletions
diff --git a/contrib/pg_stat_statements/pg_stat_statements.c b/contrib/pg_stat_statements/pg_stat_statements.c index 42f43233f89..cd4c16e9d2c 100644 --- a/contrib/pg_stat_statements/pg_stat_statements.c +++ b/contrib/pg_stat_statements/pg_stat_statements.c @@ -27,10 +27,10 @@ * to blame query costs on the proper queryId. * * To facilitate presenting entries to users, we create "representative" query - * strings in which constants are replaced with '?' characters, to make it - * clearer what a normalized entry can represent. To save on shared memory, - * and to avoid having to truncate oversized query strings, we store these - * strings in a temporary external query-texts file. Offsets into this + * strings in which constants are replaced with parameter symbols ($n), to + * make it clearer what a normalized entry can represent. To save on shared + * memory, and to avoid having to truncate oversized query strings, we store + * these strings in a temporary external query-texts file. Offsets into this * file are kept in shared memory. * * Note about locking issues: to create or delete an entry in the shared @@ -219,6 +219,9 @@ typedef struct pgssJumbleState /* Current number of valid entries in clocations array */ int clocations_count; + + /* highest Param id we've seen, in order to start normalization correctly */ + int highest_extern_param_id; } pgssJumbleState; /*---- Local variables ----*/ @@ -803,6 +806,7 @@ pgss_post_parse_analyze(ParseState *pstate, Query *query) jstate.clocations = (pgssLocationLen *) palloc(jstate.clocations_buf_size * sizeof(pgssLocationLen)); jstate.clocations_count = 0; + jstate.highest_extern_param_id = 0; /* Compute query ID and mark the Query node with it */ JumbleQuery(&jstate, query); @@ -2482,6 +2486,10 @@ JumbleExpr(pgssJumbleState *jstate, Node *node) APP_JUMB(p->paramkind); APP_JUMB(p->paramid); APP_JUMB(p->paramtype); + /* Also, track the highest external Param id */ + if (p->paramkind == PARAM_EXTERN && + p->paramid > jstate->highest_extern_param_id) + jstate->highest_extern_param_id = p->paramid; } break; case T_Aggref: @@ -2874,7 +2882,7 @@ JumbleExpr(pgssJumbleState *jstate, Node *node) break; case T_TableFunc: { - TableFunc *tablefunc = (TableFunc *) node; + TableFunc *tablefunc = (TableFunc *) node; JumbleExpr(jstate, tablefunc->docexpr); JumbleExpr(jstate, tablefunc->rowexpr); @@ -2938,7 +2946,8 @@ RecordConstLocation(pgssJumbleState *jstate, int location) * of interest, so it's worth doing.) * * *query_len_p contains the input string length, and is updated with - * the result string length (which cannot be longer) on exit. + * the result string length on exit. The resulting string might be longer + * or shorter depending on what happens with replacement of constants. * * Returns a palloc'd string. */ @@ -2949,6 +2958,7 @@ generate_normalized_query(pgssJumbleState *jstate, const char *query, char *norm_query; int query_len = *query_len_p; int i, + norm_query_buflen, /* Space allowed for norm_query */ len_to_wrt, /* Length (in bytes) to write */ quer_loc = 0, /* Source query byte location */ n_quer_loc = 0, /* Normalized query byte location */ @@ -2961,8 +2971,17 @@ generate_normalized_query(pgssJumbleState *jstate, const char *query, */ fill_in_constant_lengths(jstate, query, query_loc); + /* + * Allow for $n symbols to be longer than the constants they replace. + * Constants must take at least one byte in text form, while a $n symbol + * certainly isn't more than 11 bytes, even if n reaches INT_MAX. We + * could refine that limit based on the max value of n for the current + * query, but it hardly seems worth any extra effort to do so. + */ + norm_query_buflen = query_len + jstate->clocations_count * 10; + /* Allocate result buffer */ - norm_query = palloc(query_len + 1); + norm_query = palloc(norm_query_buflen + 1); for (i = 0; i < jstate->clocations_count; i++) { @@ -2986,8 +3005,9 @@ generate_normalized_query(pgssJumbleState *jstate, const char *query, memcpy(norm_query + n_quer_loc, query + quer_loc, len_to_wrt); n_quer_loc += len_to_wrt; - /* And insert a '?' in place of the constant token */ - norm_query[n_quer_loc++] = '?'; + /* And insert a param symbol in place of the constant token */ + n_quer_loc += sprintf(norm_query + n_quer_loc, "$%d", + i + 1 + jstate->highest_extern_param_id); quer_loc = off + tok_len; last_off = off; @@ -3004,7 +3024,7 @@ generate_normalized_query(pgssJumbleState *jstate, const char *query, memcpy(norm_query + n_quer_loc, query + quer_loc, len_to_wrt); n_quer_loc += len_to_wrt; - Assert(n_quer_loc <= query_len); + Assert(n_quer_loc <= norm_query_buflen); norm_query[n_quer_loc] = '\0'; *query_len_p = n_quer_loc; |