Google Cloud Spanner v1 API - Class Spanner.SpannerBase (5.2.0)

Reference documentation and code samples for the Google Cloud Spanner v1 API class Spanner.SpannerBase.

Base class for server-side implementations of Spanner

Creates multiple new sessions.

This API can be used to initialize a session cache on the clients. See https://goo.gl/TgSFN2 for best practices on session cache management.

Batches the supplied mutation groups in a collection of efficient transactions. All mutations in a group are committed atomically. However, mutations across groups can be committed non-atomically in an unspecified order and thus, they must be independent of each other. Partial failure is possible, that is, some groups might have been committed successfully, while some might have failed. The results of individual batches are streamed into the response as the batches are applied.

BatchWrite requests are not replay protected, meaning that each mutation group can be applied more than once. Replays of non-idempotent mutations can have undesirable effects. For example, replays of an insert mutation can produce an already exists error or if you use generated or commit timestamp-based keys, it can result in additional rows being added to the mutation's table. We recommend structuring your mutation groups to be idempotent to avoid this issue.

Begins a new transaction. This step can often be skipped: [Read][google.spanner.v1.Spanner.Read], [ExecuteSql][google.spanner.v1.Spanner.ExecuteSql] and [Commit][google.spanner.v1.Spanner.Commit] can begin a new transaction as a side-effect.

Commits a transaction. The request includes the mutations to be applied to rows in the database.

Commit might return an ABORTED error. This can occur at any time; commonly, the cause is conflicts with concurrent transactions. However, it can also happen for a variety of other reasons. If Commit returns ABORTED, the caller should retry the transaction from the beginning, reusing the same session.

On very rare occasions, Commit might return UNKNOWN. This can happen, for example, if the client job experiences a 1+ hour networking failure. At that point, Cloud Spanner has lost track of the transaction outcome and we recommend that you perform another read from the database to see the state of things as they are now.

Creates a new session. A session can be used to perform transactions that read and/or modify data in a Cloud Spanner database. Sessions are meant to be reused for many consecutive transactions.

Sessions can only execute one transaction at a time. To execute multiple concurrent read-write/write-only transactions, create multiple sessions. Note that standalone reads and queries use a transaction internally, and count toward the one transaction limit.

Active sessions use additional server resources, so it's a good idea to delete idle and unneeded sessions. Aside from explicit deletes, Cloud Spanner can delete sessions when no operations are sent for more than an hour. If a session is deleted, requests to it return NOT_FOUND.

Idle sessions can be kept alive by sending a trivial SQL query periodically, for example, "SELECT 1".

Ends a session, releasing server resources associated with it. This asynchronously triggers the cancellation of any operations that are running with this session.

Executes a batch of SQL DML statements. This method allows many statements to be run with lower latency than submitting them sequentially with [ExecuteSql][google.spanner.v1.Spanner.ExecuteSql].

Statements are executed in sequential order. A request can succeed even if a statement fails. The [ExecuteBatchDmlResponse.status][google.spanner.v1.ExecuteBatchDmlResponse.status] field in the response provides information about the statement that failed. Clients must inspect this field to determine whether an error occurred.

Execution stops after the first failed statement; the remaining statements are not executed.

Executes an SQL statement, returning all results in a single reply. This method can't be used to return a result set larger than 10 MiB; if the query yields more data than that, the query fails with a FAILED_PRECONDITION error.

Operations inside read-write transactions might return ABORTED. If this occurs, the application should restart the transaction from the beginning. See [Transaction][google.spanner.v1.Transaction] for more details.

Larger result sets can be fetched in streaming fashion by calling [ExecuteStreamingSql][google.spanner.v1.Spanner.ExecuteStreamingSql] instead.

The query string can be SQL or Graph Query Language (GQL).

Like [ExecuteSql][google.spanner.v1.Spanner.ExecuteSql], except returns the result set as a stream. Unlike [ExecuteSql][google.spanner.v1.Spanner.ExecuteSql], there is no limit on the size of the returned result set. However, no individual row in the result set can exceed 100 MiB, and no column value can exceed 10 MiB.

The query string can be SQL or Graph Query Language (GQL).

Gets a session. Returns NOT_FOUND if the session doesn't exist. This is mainly useful for determining whether a session is still alive.

Lists all sessions in a given database.

Creates a set of partition tokens that can be used to execute a query operation in parallel. Each of the returned partition tokens can be used by [ExecuteStreamingSql][google.spanner.v1.Spanner.ExecuteStreamingSql] to specify a subset of the query result to read. The same session and read-only transaction must be used by the PartitionQueryRequest used to create the partition tokens and the ExecuteSqlRequests that use the partition tokens.

Partition tokens become invalid when the session used to create them is deleted, is idle for too long, begins a new transaction, or becomes too old. When any of these happen, it isn't possible to resume the query, and the whole operation must be restarted from the beginning.

Creates a set of partition tokens that can be used to execute a read operation in parallel. Each of the returned partition tokens can be used by [StreamingRead][google.spanner.v1.Spanner.StreamingRead] to specify a subset of the read result to read. The same session and read-only transaction must be used by the PartitionReadRequest used to create the partition tokens and the ReadRequests that use the partition tokens. There are no ordering guarantees on rows returned among the returned partition tokens, or even within each individual StreamingRead call issued with a partition_token.

Partition tokens become invalid when the session used to create them is deleted, is idle for too long, begins a new transaction, or becomes too old. When any of these happen, it isn't possible to resume the read, and the whole operation must be restarted from the beginning.

Reads rows from the database using key lookups and scans, as a simple key/value style alternative to [ExecuteSql][google.spanner.v1.Spanner.ExecuteSql]. This method can't be used to return a result set larger than 10 MiB; if the read matches more data than that, the read fails with a FAILED_PRECONDITION error.

Reads inside read-write transactions might return ABORTED. If this occurs, the application should restart the transaction from the beginning. See [Transaction][google.spanner.v1.Transaction] for more details.

Larger result sets can be yielded in streaming fashion by calling [StreamingRead][google.spanner.v1.Spanner.StreamingRead] instead.

Rolls back a transaction, releasing any locks it holds. It's a good idea to call this for any transaction that includes one or more [Read][google.spanner.v1.Spanner.Read] or [ExecuteSql][google.spanner.v1.Spanner.ExecuteSql] requests and ultimately decides not to commit.

Rollback returns OK if it successfully aborts the transaction, the transaction was already aborted, or the transaction isn't found. Rollback never returns ABORTED.

Like [Read][google.spanner.v1.Spanner.Read], except returns the result set as a stream. Unlike [Read][google.spanner.v1.Spanner.Read], there is no limit on the size of the returned result set. However, no individual row in the result set can exceed 100 MiB, and no column value can exceed 10 MiB.