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EXPLAIN JSON: Print out the "expensive constant condition" attached to joins.

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This commit is contained in:
Sergei Petrunia
2014-12-06 19:27:42 +03:00
parent 5ee1c25fa8
commit dc259324d7
5 changed files with 104 additions and 5 deletions
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29
sql/sql_explain.cc
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@ -27,6 +27,8 @@ const char * STR_DELETING_ALL_ROWS= "Deleting all rows";
const char * STR_IMPOSSIBLE_WHERE= "Impossible WHERE";
const char * STR_NO_ROWS_AFTER_PRUNING= "No matching rows after partition pruning";
static void write_item(Json_writer *writer, Item *item);
Explain_query::Explain_query(THD *thd_arg, MEM_ROOT *root) :
mem_root(root), upd_del_plan(NULL), insert_plan(NULL),
unions(root), selects(root), thd(thd_arg), apc_enabled(false),
@ -732,7 +734,17 @@ void Explain_select::print_explain_json(Explain_query *query,
Explain_basic_join does not have ORDER/GROUP.
A: factor out join tab printing loop into a common func.
*/
Explain_basic_join::print_explain_json(query, writer, is_analyze);
writer->add_member("query_block").start_object();
writer->add_member("select_id").add_ll(select_id);
if (exec_const_cond)
{
writer->add_member("const_condition");
write_item(writer, exec_const_cond);
}
Explain_basic_join::print_explain_json_interns(query, writer, is_analyze);
writer->end_object();
}
}
@ -742,10 +754,20 @@ void Explain_basic_join::print_explain_json(Explain_query *query,
Json_writer *writer,
bool is_analyze)
{
Json_writer_nesting_guard guard(writer);
writer->add_member("query_block").start_object();
writer->add_member("select_id").add_ll(select_id);
print_explain_json_interns(query, writer, is_analyze);
writer->end_object();
}
void Explain_basic_join::print_explain_json_interns(Explain_query *query,
Json_writer *writer,
bool is_analyze)
{
Json_writer_nesting_guard guard(writer);
for (uint i=0; i< n_join_tabs; i++)
{
if (join_tabs[i]->start_dups_weedout)
@ -757,7 +779,6 @@ void Explain_basic_join::print_explain_json(Explain_query *query,
writer->end_object();
}
print_explain_json_for_children(query, writer, is_analyze);
writer->end_object();
}