Hi Marc (cc to the list),

If the database replacement is defined as a single REST operation, you won’t encounter any problems; other transactions will need to wait until your database has been fully created.

Best, Christian

Marc Coenegracht marc@crosseyed.nl schrieb am Do., 9. Aug. 2018, 00:21:

Hi Christian,

Thanks for the quick answer.

Defining the operations in a single query would be preferable but isn't possible, since the read operation is simply triggered by a website visitor, and the creation of the new DB (indeed overwriting the old DB with db:create) is performed by an action of the CMS admin.

So, these operations can happen at the exact same moment. The inconvenience at the front-end will be minimal, I'm just wondering if these concurrent operations can cause problems with BaseX or the db:create operation.

best, Marc

On Wed, 8 Aug 2018, Christian Grün wrote:

...

Hi Marc,

As one XQuery expression is one transaction, the best approach is to define your operations in a single query. If you call db:create, an existing database will be overwritten, and the function allows you to specify some initial input.

Hope this helps, Christian

On Wed, Aug 8, 2018 at 10:31 PM Marc Coenegracht marc@crosseyed.nl

wrote:

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...

Hi,

A CMS occasionally recreates some existing databases of a production

site.

...

...

The databases are deleted and again created with the new content within a few seconds.

What happens if a read operation is taking place during this process?

Can

...

...

it cause problems with the recreation of the DB or with the BaseX server instance?

Of course it is possible to update the databases instead, but this

process

...

...

is a lot simpler and probably faster too.

All operations are executed running xquery scripts with REST using the BaseX http server.

Marc