You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
26 lines
1.2 KiB
ReStructuredText
26 lines
1.2 KiB
ReStructuredText
====================================
|
|
Stored relations and transactions
|
|
====================================
|
|
|
|
The first thing to know before we get into the topic is that you can execute multiple queries in one go,
|
|
by wrapping each query in curly braces ``{}``. Each query can have its own independent query options.
|
|
Execution proceeds for each query serially, and aborts at the first error encountered.
|
|
The returned relation is that of the last query.
|
|
|
|
Multiple queries passed in one go are executed in a single transaction. Within the transaction,
|
|
execution of queries adheres to multi-version concurrency control: only data that are already committed,
|
|
or written within the same transaction, are read,
|
|
and at the end of the transaction, any changes to stored relations are only committed if there are no conflicts
|
|
and no errors are raised.
|
|
|
|
---------------------------
|
|
Using stored relations
|
|
---------------------------
|
|
|
|
------------------------------------------------------
|
|
Chaining queries into a single transaction
|
|
------------------------------------------------------
|
|
|
|
------------------------------------------------------
|
|
Using transactions to make indices
|
|
------------------------------------------------------ |