— Clean environment
drop table gtt;
drop table gtt
*
ERROR at line 1:
ORA-00942: table or view does not exist<\/p>\n
— Global temporary – preserve rows
create global temporary table gtt ( x int ) on commit preserve rows;
Table created.<\/p>\n
— Keeps information until the end of the user session
select duration from user_tables where table_name = ‘GTT’;
DURATION
—————
SYS$SESSION<\/p>\n
— Insert one row
insert into gtt values(1);
1 row created.<\/p>\n
— Creates a TO lock
select sid, type, id1, id2, lmode from v$lock where id1=(select object_id from all_objects where object_name=’GTT’);
SID TY ID1 ID2 LMODE
———- — ———- ———- ———-
4343 TO 403115 1 3<\/p>\n
— Commit transaction
commit;
Commit complete.<\/p>\n
— TO lock continues…
select sid, type, id1, id2, lmode from v$lock where id1=(select object_id from all_objects where object_name=’GTT’);
SID TY ID1 ID2 LMODE
———- — ———- ———- ———-
4343 TO 403115 1 3<\/p>\n
— Any user that tries to change the table
— Will receive: ORA-14450: attempt to access a transactional temp table already in use
alter table gtt add (y int);
alter table gtt add (y int)
*
ERROR at line 1:
ORA-14450: attempt to access a transactional temp table already in use<\/p>\n
— Only after doing truncate
truncate table gtt;
Table truncated.<\/p>\n
— TO lock disappears
select * from v$lock where id1=(select object_id from all_objects where object_name=’GTT’);
no rows selected<\/p>\n
— With a global temporary table delete rows
drop table gtt;
Table dropped.<\/p>\n
create global temporary table gtt ( x int ) on commit delete rows;
Table created.<\/p>\n
— The duration is at transaction level
select duration from user_tables where table_name = ‘GTT’;
DURATION
—————
SYS$TRANSACTION<\/p>\n
— Insert one row
insert into gtt values(1);
1 row created.<\/p>\n
— Creates a TO lock
select sid, type, id1, id2, lmode from v$lock where id1=(select object_id from all_objects where object_name=’GTT’);
SID TY ID1 ID2 LMODE
———- — ———- ———- ———-
4343 TO 403116 1 3<\/p>\n
— That disappears as soon as you commit the transaction
commit;
Commit complete.<\/p>\n
select sid, type, id1, id2, lmode from v$lock where id1=(select object_id from all_objects where object_name=’GTT’);
no rows selected<\/p>\n
— Clean up environment
drop table gtt;
Table dropped.<\/p>\n","protected":false},"excerpt":{"rendered":"
— Clean environment drop table gtt; drop table gtt *ERROR at line 1:ORA-00942: table or view does not exist — Global temporary – preserve rowscreate global temporary table gtt ( x int ) on commit preserve rows;Table created. — Keeps information until the end of the user sessionselect duration from user_tables where table_name = ‘GTT’;DURATION—————SYS$SESSION — Insert […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6],"tags":[],"class_list":["post-25","post","type-post","status-publish","format-standard","category-oracle","czr-hentry"],"_links":{"self":[{"href":"https:\/\/anjo.pt\/keyword-oracle\/wp-json\/wp\/v2\/posts\/25","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/anjo.pt\/keyword-oracle\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/anjo.pt\/keyword-oracle\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/anjo.pt\/keyword-oracle\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/anjo.pt\/keyword-oracle\/wp-json\/wp\/v2\/comments?post=25"}],"version-history":[{"count":1,"href":"https:\/\/anjo.pt\/keyword-oracle\/wp-json\/wp\/v2\/posts\/25\/revisions"}],"predecessor-version":[{"id":169,"href":"https:\/\/anjo.pt\/keyword-oracle\/wp-json\/wp\/v2\/posts\/25\/revisions\/169"}],"wp:attachment":[{"href":"https:\/\/anjo.pt\/keyword-oracle\/wp-json\/wp\/v2\/media?parent=25"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/anjo.pt\/keyword-oracle\/wp-json\/wp\/v2\/categories?post=25"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/anjo.pt\/keyword-oracle\/wp-json\/wp\/v2\/tags?post=25"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}