[whatwg] Database API: transaction can get help open too long

[Aaron Boodman]

I noticed one unfortunate thing about the new Database API. Because
the executeSql() callback holds open the transaction, it is easy to
accidentally do intensive work inside there and hold open the
transaction too long. A common mistake might be to do a big select and
then hold open the transaction while the UI is updated. This could
hold open the tx maybe an extra couple hundred ms. A bigger problem
would be to do synchronous XHR (for example, in workers). This could
hold open the tx for seconds.

The right place to do work like this is in transaction()'s success
callback. But because the resultsets aren't easily accessible there, I
think authors are more likely to do work in executeSql()'s success
callback and use transaction()'s success callback less frequently.

Off hand about the best solution I can think of to this problem is to
have some sort of state on the transaction object that gathers the
results.

This is not very satisfying though. Does anyone have a better idea? Or
think this is not a big enough concern to worry about?

- a