diff options
Diffstat (limited to 'sql')
| -rw-r--r-- | sql/my_json_writer.h | 8 | ||||
| -rw-r--r-- | sql/opt_subselect.cc | 13 | ||||
| -rw-r--r-- | sql/opt_trace.cc | 60 | ||||
| -rw-r--r-- | sql/opt_trace.h | 38 | ||||
| -rw-r--r-- | sql/opt_trace_context.h | 6 | ||||
| -rw-r--r-- | sql/sql_derived.cc | 30 | ||||
| -rw-r--r-- | sql/sql_parse.cc | 4 | ||||
| -rw-r--r-- | sql/sql_prepare.cc | 11 | ||||
| -rw-r--r-- | sql/sql_select.cc | 17 |
9 files changed, 145 insertions, 42 deletions
diff --git a/sql/my_json_writer.h b/sql/my_json_writer.h index d82313f996f..20f479dc6d0 100644 --- a/sql/my_json_writer.h +++ b/sql/my_json_writer.h @@ -224,6 +224,14 @@ public: size_t get_truncated_bytes() { return output.get_truncated_bytes(); } + /* + Note: this may not return exact value due to pretty-printer doing + buffering + */ + size_t get_written_size() { + return output.length() + output.get_truncated_bytes(); + } + Json_writer() : indent_level(0), document_start(true), element_started(false), first_child(true) diff --git a/sql/opt_subselect.cc b/sql/opt_subselect.cc index d91557c5be2..953f2af0be8 100644 --- a/sql/opt_subselect.cc +++ b/sql/opt_subselect.cc @@ -549,6 +549,12 @@ bool is_materialization_applicable(THD *thd, Item_in_subselect *in_subs, and, depending on the rewrite, either do it, or record it to be done at a later phase. + NOTE + * This function called at Prepare phase. It should NOT do any rewrites. + It only collects information that's used for doing the rewrites at the + optimization phase. + * Optimizer trace is NOT yet enabled when this function is called. + RETURN 0 - OK Other - Some sort of query error @@ -703,8 +709,6 @@ int check_and_do_in_subquery_rewrites(JOIN *join) { DBUG_PRINT("info", ("Subquery is semi-join conversion candidate")); - (void)subquery_types_allow_materialization(thd, in_subs); - in_subs->is_flattenable_semijoin= TRUE; /* Register the subquery for further processing in flatten_subqueries() */ @@ -717,10 +721,6 @@ int check_and_do_in_subquery_rewrites(JOIN *join) if (arena) thd->restore_active_arena(arena, &backup); in_subs->is_registered_semijoin= TRUE; - OPT_TRACE_TRANSFORM(thd, trace_wrapper, trace_transform, - select_lex->select_number, - "IN (SELECT)", "semijoin"); - trace_transform.add("chosen", true); } } else @@ -1262,6 +1262,7 @@ bool convert_join_subqueries_to_semijoins(JOIN *join) while ((in_subq= li++)) { bool remove_item= TRUE; + (void)subquery_types_allow_materialization(thd, in_subq); /* Stop processing if we've reached a subquery that's attached to the ON clause */ if (in_subq->do_not_convert_to_sj) diff --git a/sql/opt_trace.cc b/sql/opt_trace.cc index ba9220cac44..2227519d991 100644 --- a/sql/opt_trace.cc +++ b/sql/opt_trace.cc @@ -106,6 +106,27 @@ inline bool sql_command_can_be_traced(enum enum_sql_command sql_command) sql_command == SQLCOM_UPDATE_MULTI; } + +void opt_trace_print_expanded_union(THD *thd, SELECT_LEX_UNIT *unit, + Json_writer_object *writer) +{ + DBUG_ASSERT(thd->trace_started()); + + StringBuffer<1024> str(system_charset_info); + ulonglong save_option_bits= thd->variables.option_bits; + thd->variables.option_bits &= ~OPTION_QUOTE_SHOW_CREATE; + unit->print(&str, enum_query_type(QT_TO_SYSTEM_CHARSET | + QT_SHOW_SELECT_NUMBER | + QT_ITEM_IDENT_SKIP_DB_NAMES | + QT_VIEW_INTERNAL)); + thd->variables.option_bits= save_option_bits; + /* + The output is not very pretty lots of back-ticks, the output + is as the one in explain extended , lets try to improved it here. + */ + writer->add("expanded_query", str.c_ptr_safe(), str.length()); +} + void opt_trace_print_expanded_query(THD *thd, SELECT_LEX *select_lex, Json_writer_object *writer) @@ -499,10 +520,49 @@ Opt_trace_start::Opt_trace_start(THD *thd, TABLE_LIST *tbl, } } + +/* + @brief + See "Handing Query Errors" section of comment for Opt_trace_start +*/ + +void Opt_trace_start::trace_heading_done() +{ + Json_writer *w; + if (traceable && (w= ctx->get_current_json())) + trace_heading_size= w->get_written_size(); + else + trace_heading_size= 0; +} + + +/* + @brief + See "Handing Query Errors" section of comment for Opt_trace_start + + @detail + We can't delete the trace right now, because some final writes (e.g. + the top-level closing '}' will still be made to it. Just set clean_me=true + so that it is deleted instead of saving it. +*/ + +void Opt_trace_start::clean_empty_trace() +{ + Json_writer *w; + if (traceable && (w= ctx->get_current_json())) + { + if (w->get_written_size() == trace_heading_size) + clean_me= true; + } +} + + Opt_trace_start::~Opt_trace_start() { if (traceable) { + if (clean_me) + ctx->abort_trace(); ctx->end(); traceable= FALSE; } diff --git a/sql/opt_trace.h b/sql/opt_trace.h index 101fb5f707e..c6583cdab80 100644 --- a/sql/opt_trace.h +++ b/sql/opt_trace.h @@ -69,10 +69,34 @@ struct Opt_trace_info @param query query @param length query's length @param charset charset which was used to encode this query + + @detail + == Lifecycle == + The trace is created before the Name Resolution phase. Reasons: + 1. This way, we can have one place where we start the trace for all kinds of + queries. If we tried to start tracing right before query optimization + starts, we would have to construct Opt_trace_start object in many + places: one for SELECT, for UPDATE, for DELETE, etc. + + 2. Privilege checking code may notify the trace that the user doesn't have + enough permissions to perform tracing. The trace must exist to receive + the notication. See missing_privilege() and the opt_trace_disable_if_... + functions below for details. + + == Handling Query Errors == + The trace is kept when query error occurs, except for the case when + nothing [meaningful] was traced. The second part is necessary for mtr to + produce the same output with and without --ps-protocol. If there is an + error on prepare phase, then: + - In --ps-protocol: PREPARE command produces no trace. The EXECUTE + command is not run. The trace is not generated at all. + - Regular SQL query: should also NOT produce any trace to match the above. + This is handled by trace_heading_done() and clean_empty_trace(). */ -class Opt_trace_start { +class Opt_trace_start +{ public: Opt_trace_start(THD *thd_arg, TABLE_LIST *tbl, enum enum_sql_command sql_command, @@ -82,8 +106,17 @@ class Opt_trace_start { const CHARSET_INFO *query_charset); ~Opt_trace_start(); + void trace_heading_done(); + void clean_empty_trace(); private: Opt_trace_context *const ctx; + + /* Number of bytes written to the trace after the heading was written/ */ + size_t trace_heading_size; + + /* If true, trace should be removed (See Handling Query Errors above) */ + bool clean_me= false; + /* True: the query will be traced False: otherwise @@ -102,6 +135,9 @@ class Opt_trace_start { void opt_trace_print_expanded_query(THD *thd, SELECT_LEX *select_lex, Json_writer_object *trace_object); +void opt_trace_print_expanded_union(THD *thd, SELECT_LEX_UNIT *unit, + Json_writer_object *writer); + void add_table_scan_values_to_trace(THD *thd, JOIN_TAB *tab); void trace_plan_prefix(JOIN *join, uint idx, table_map join_tables); void print_final_join_order(JOIN *join); diff --git a/sql/opt_trace_context.h b/sql/opt_trace_context.h index f578a0c67ec..ae77c94fdc2 100644 --- a/sql/opt_trace_context.h +++ b/sql/opt_trace_context.h @@ -114,6 +114,12 @@ public: bool is_enabled(); + void abort_trace() + { + delete current_trace; + current_trace= NULL; + } + void missing_privilege(); static const char *flag_names[]; diff --git a/sql/sql_derived.cc b/sql/sql_derived.cc index 579ea34b8e4..cf878ad29c0 100644 --- a/sql/sql_derived.cc +++ b/sql/sql_derived.cc @@ -420,6 +420,24 @@ bool mysql_derived_merge(THD *thd, LEX *lex, TABLE_LIST *derived) goto exit_merge; } + if (unlikely(thd->trace_started())) + { + /* + Add to optimizer trace whether a derived table/view + is merged into the parent select or not. + */ + OPT_TRACE_VIEWS_TRANSFORM(thd, trace_wrapper, trace_derived, + derived->is_derived() ? "derived" : "view", + derived->alias.str ? derived->alias.str : "<NULL>", + derived->get_unit()->first_select()->select_number, + derived->is_merged_derived() ? "merged" : "materialized"); + if (derived->is_merged_derived()) + { + opt_trace_print_expanded_union(thd, derived->get_unit(), + &trace_derived); + } + } + /* exclude select lex so it doesn't show up in explain. do this only for derived table as for views this is already done. @@ -822,18 +840,6 @@ bool mysql_derived_prepare(THD *thd, LEX *lex, TABLE_LIST *derived) } } - if (unlikely(thd->trace_started())) - { - /* - Add to optimizer trace whether a derived table/view - is merged into the parent select or not. - */ - OPT_TRACE_VIEWS_TRANSFORM(thd, trace_wrapper, trace_derived, - derived->is_derived() ? "derived" : "view", - derived->alias.str ? derived->alias.str : "<NULL>", - derived->get_unit()->first_select()->select_number, - derived->is_merged_derived() ? "merged" : "materialized"); - } /* Above cascade call of prepare is important for PS protocol, but after it is called we can check if we really need prepare for this derived diff --git a/sql/sql_parse.cc b/sql/sql_parse.cc index b9d3eec5a60..b19ac276267 100644 --- a/sql/sql_parse.cc +++ b/sql/sql_parse.cc @@ -3648,6 +3648,7 @@ mysql_execute_command(THD *thd, bool is_called_from_prepared_stmt) Json_writer_object trace_command(thd); Json_writer_array trace_command_steps(thd, "steps"); + ots.trace_heading_done(); /* store old value of binlog format */ enum_binlog_format orig_binlog_format,orig_current_stmt_binlog_format; @@ -6154,6 +6155,9 @@ finish: thd->wsrep_PA_safe= true; #endif /* WITH_WSREP */ + if (res || thd->is_error()) + ots.clean_empty_trace(); + DBUG_RETURN(res || thd->is_error()); } diff --git a/sql/sql_prepare.cc b/sql/sql_prepare.cc index cc6f572ea64..b6bc9eff50e 100644 --- a/sql/sql_prepare.cc +++ b/sql/sql_prepare.cc @@ -2435,17 +2435,6 @@ static bool check_prepared_statement(Prepared_statement *stmt) lex->first_select_lex()->context.resolve_in_table_list_only(select_lex-> get_table_list()); - /* - For the optimizer trace, this is the symmetric, for statement preparation, - of what is done at statement execution (in mysql_execute_command()). - */ - Opt_trace_start ots(thd, tables, lex->sql_command, &lex->var_list, - thd->query(), thd->query_length(), - thd->variables.character_set_client); - - Json_writer_object trace_command(thd); - Json_writer_array trace_command_steps(thd, "steps"); - /* Reset warning count for each query that uses tables */ if (tables) thd->get_stmt_da()->opt_clear_warning_info(thd->query_id); diff --git a/sql/sql_select.cc b/sql/sql_select.cc index a357d4f8c8a..45d8f54e264 100644 --- a/sql/sql_select.cc +++ b/sql/sql_select.cc @@ -1287,11 +1287,6 @@ JOIN::prepare(TABLE_LIST *tables_init, COND *conds_init, uint og_num, join_list= &select_lex->top_join_list; union_part= unit_arg->is_unit_op(); - Json_writer_object trace_wrapper(thd); - Json_writer_object trace_prepare(thd, "join_preparation"); - trace_prepare.add_select_number(select_lex->select_number); - Json_writer_array trace_steps(thd, "steps"); - // simple check that we got usable conds dbug_print_item(conds); @@ -1675,12 +1670,6 @@ JOIN::prepare(TABLE_LIST *tables_init, COND *conds_init, uint og_num, } } - if (thd->trace_started()) - { - Json_writer_object trace_wrapper(thd); - opt_trace_print_expanded_query(thd, select_lex, &trace_wrapper); - } - if (!procedure && result && result->prepare(fields_list, unit_arg)) goto err; /* purecov: inspected */ @@ -1985,7 +1974,11 @@ JOIN::optimize_inner() Json_writer_object trace_wrapper(thd); Json_writer_object trace_prepare(thd, "join_optimization"); - trace_prepare.add_select_number(select_lex->select_number); + if (thd->trace_started()) + { + trace_prepare.add_select_number(select_lex->select_number); + opt_trace_print_expanded_query(thd, select_lex, &trace_prepare); + } Json_writer_array trace_steps(thd, "steps"); /* |