Hi all,
I am working on a project which allows multiple users to work on single
large text document. I am using lo_put to apply only the diff into the
large object without replacing it with a new lob. While working on it, I
encountered an error "Tuple concurrently updated".
The error can be reproduced with two psql clients.
Setup:
mydb=# create table text_docs(id serial primary key, data oid);
CREATE TABLE
mydb=# insert into text_docs(data) select lo_import('./upload.txt');
INSERT 0 1
mydb=# select * from text_docs;
id | data
----+---------
1 | 5810130
(1 rows)
Now, if we open two psql clients and execute the following commands:
Client 1:
mydb=# begin;
BEGIN
mydb=# select lo_put(5810130, 10, '\xaa');
UPDATE 1
Client 2:
mydb=# select lo_put(5810130, 10, '\xaa');
Client 1:
mydb=# commit;
COMMIT
Client 2:
mydb=# select lo_put(5810130, 10, '\xaa');
ERROR: tuple concurrently updated
Is there a workaround to this concurrency issue without creating a new
large object?
Regards
Shalini
