Hello,

I am running a java program which connects to a MonetDB database and runs a thread where each thread creates a number of local temporary tables using the  and populates these tables in certain data processing steps. On termination the temporary tables are deleted. These temporary tables are utilised in a number of select statements in combination with the tables in the database.   Tables are created using a table name where a UUID is generated for each thread so the use of local tables is unique to the thread e.g.

create local temporary table tempquerywords0e5a0e08c1d24cf6b9529426463b6191(word_word varchar(255)) ON COMMIT PRESERVE ROWS. All needed temporary tables are created by the thread as an initial process.

The connection to the database is set with autoCommit set to true.

If each thread is run sequentially , there is no problem. However if I run the process concurrently with a maximum of 2 concurrent threads, some threads terminate early with an Exception message e.g.

nested exception is java.sql.SQLException: SELECT: no such table 'tempweightedclustersa7f7f47e7c184175ac8ab5ee2dc76a03'. This message is confusing as the table is populated ok before the select.

Although other participants have posted messages concerning problems based on concurrent updates and temporary tables , is there an issue concerning concurrent reads and temporary tables?

Best Regards

Niall