Database Reference
In-Depth Information
For example, suppose you give Alice access to read your
Logs
dataset, but
Alice is not a member of the project team. She can read values out of the
dataset, but if she wants to run a query, she needs to run in some project
where she is a member of the team. Then, if Bob is an editor on the project
team but you remove him from the ACL of the
Sekret
dataset, Bob cannot
run queries against, read data from, or even see that the
Sekret
dataset
exists.
Jobs
In BigQuery, when you want to get something done—adding data, running
a query, copying a table, and so on—you use a
job
. Jobs are asynchronous
operations that BigQuery performs on a user's behalf. Some jobs, like Query
jobs, may have convenient API wrappers that make them appear to be
synchronous, but under the covers they're still asynchronous operations.
You can check their status while they're running, and you can come back and
get the results later via a separate API call.
Job Components
Jobs have four main parts: a reference, which is a unique name for the job;
a configuration that tells BigQuery what to run; status of the job, which
includes errors and warnings; and job statistics to provide information
about what the job accomplished. Let's consider each of these job parts in
turn.
Job References
Job references
are immutable names for a job. They can be used to look
up the status of a job when it is running or statistics when the job has
completed. They can be used by project owners to figure out what was run in
their project and by whom. Job references are also useful when contacting
BigQuery support about a problem; the support engineer or BigQuery
developer can use the job ID to look up what happened and figure out what
went wrong.
There are two parts of a job reference: a
project ID
and a
job ID
. Project
IDs can be either the project number or project ID discussed earlier in this
chapter (not the project friendly name, however). All jobs run in the context
of a project that indicates who is responsible for paying the bills for any work
