Cloud Spanner V1 Client - Class PBReadOnly (1.82.0)

Reference documentation and code samples for the Cloud Spanner V1 Client class PBReadOnly.

Message type to initiate a read-only transaction.

Generated from protobuf message google.spanner.v1.TransactionOptions.ReadOnly

Namespace

Google \ Cloud \ Spanner \ V1 \ TransactionOptions

Methods

__construct

Constructor.

Parameters
Name Description
data array

Optional. Data for populating the Message object.
↳ strong bool

Read at a timestamp where all previously committed transactions are visible.
↳ min_read_timestamp Google\Protobuf\Timestamp

Executes all reads at a timestamp >= min_read_timestamp. This is useful for requesting fresher data than some previous read, or data that is fresh enough to observe the effects of some previously committed transaction whose timestamp is known. Note that this option can only be used in single-use transactions. A timestamp in RFC3339 UTC "Zulu" format, accurate to nanoseconds. Example: "2014-10-02T15:01:23.045123456Z".
↳ max_staleness Google\Protobuf\Duration

Read data at a timestamp >= NOW - max_staleness seconds. Guarantees that all writes that have committed more than the specified number of seconds ago are visible. Because Cloud Spanner chooses the exact timestamp, this mode works even if the client's local clock is substantially skewed from Cloud Spanner commit timestamps. Useful for reading the freshest data available at a nearby replica, while bounding the possible staleness if the local replica has fallen behind. Note that this option can only be used in single-use transactions.
↳ read_timestamp Google\Protobuf\Timestamp

Executes all reads at the given timestamp. Unlike other modes, reads at a specific timestamp are repeatable; the same read at the same timestamp always returns the same data. If the timestamp is in the future, the read will block until the specified timestamp, modulo the read's deadline. Useful for large scale consistent reads such as mapreduces, or for coordinating many reads against a consistent snapshot of the data. A timestamp in RFC3339 UTC "Zulu" format, accurate to nanoseconds. Example: "2014-10-02T15:01:23.045123456Z".
↳ exact_staleness Google\Protobuf\Duration

Executes all reads at a timestamp that is exact_staleness old. The timestamp is chosen soon after the read is started. Guarantees that all writes that have committed more than the specified number of seconds ago are visible. Because Cloud Spanner chooses the exact timestamp, this mode works even if the client's local clock is substantially skewed from Cloud Spanner commit timestamps. Useful for reading at nearby replicas without the distributed timestamp negotiation overhead of max_staleness.
↳ return_read_timestamp bool

If true, the Cloud Spanner-selected read timestamp is included in the Transaction message that describes the transaction.

getStrong

Read at a timestamp where all previously committed transactions are visible.

Returns
Type Description
bool

hasStrong

setStrong

Read at a timestamp where all previously committed transactions are visible.

Parameter
Name Description
var bool
Returns
Type Description
$this

getMinReadTimestamp

Executes all reads at a timestamp >= min_read_timestamp.

This is useful for requesting fresher data than some previous read, or data that is fresh enough to observe the effects of some previously committed transaction whose timestamp is known. Note that this option can only be used in single-use transactions. A timestamp in RFC3339 UTC "Zulu" format, accurate to nanoseconds. Example: "2014-10-02T15:01:23.045123456Z".

Returns
Type Description
Google\Protobuf\Timestamp|null

hasMinReadTimestamp

setMinReadTimestamp

Executes all reads at a timestamp >= min_read_timestamp.

This is useful for requesting fresher data than some previous read, or data that is fresh enough to observe the effects of some previously committed transaction whose timestamp is known. Note that this option can only be used in single-use transactions. A timestamp in RFC3339 UTC "Zulu" format, accurate to nanoseconds. Example: "2014-10-02T15:01:23.045123456Z".

Parameter
Name Description
var Google\Protobuf\Timestamp
Returns
Type Description
$this

getMaxStaleness

Read data at a timestamp >= NOW - max_staleness seconds. Guarantees that all writes that have committed more than the specified number of seconds ago are visible. Because Cloud Spanner chooses the exact timestamp, this mode works even if the client's local clock is substantially skewed from Cloud Spanner commit timestamps.

Useful for reading the freshest data available at a nearby replica, while bounding the possible staleness if the local replica has fallen behind. Note that this option can only be used in single-use transactions.

Returns
Type Description
Google\Protobuf\Duration|null

hasMaxStaleness

setMaxStaleness

Read data at a timestamp >= NOW - max_staleness seconds. Guarantees that all writes that have committed more than the specified number of seconds ago are visible. Because Cloud Spanner chooses the exact timestamp, this mode works even if the client's local clock is substantially skewed from Cloud Spanner commit timestamps.

Useful for reading the freshest data available at a nearby replica, while bounding the possible staleness if the local replica has fallen behind. Note that this option can only be used in single-use transactions.

Parameter
Name Description
var Google\Protobuf\Duration
Returns
Type Description
$this

getReadTimestamp

Executes all reads at the given timestamp. Unlike other modes, reads at a specific timestamp are repeatable; the same read at the same timestamp always returns the same data. If the timestamp is in the future, the read will block until the specified timestamp, modulo the read's deadline.

Useful for large scale consistent reads such as mapreduces, or for coordinating many reads against a consistent snapshot of the data. A timestamp in RFC3339 UTC "Zulu" format, accurate to nanoseconds. Example: "2014-10-02T15:01:23.045123456Z".

Returns
Type Description
Google\Protobuf\Timestamp|null

hasReadTimestamp

setReadTimestamp

Executes all reads at the given timestamp. Unlike other modes, reads at a specific timestamp are repeatable; the same read at the same timestamp always returns the same data. If the timestamp is in the future, the read will block until the specified timestamp, modulo the read's deadline.

Useful for large scale consistent reads such as mapreduces, or for coordinating many reads against a consistent snapshot of the data. A timestamp in RFC3339 UTC "Zulu" format, accurate to nanoseconds. Example: "2014-10-02T15:01:23.045123456Z".

Parameter
Name Description
var Google\Protobuf\Timestamp
Returns
Type Description
$this

getExactStaleness

Executes all reads at a timestamp that is exact_staleness old. The timestamp is chosen soon after the read is started.

Guarantees that all writes that have committed more than the specified number of seconds ago are visible. Because Cloud Spanner chooses the exact timestamp, this mode works even if the client's local clock is substantially skewed from Cloud Spanner commit timestamps. Useful for reading at nearby replicas without the distributed timestamp negotiation overhead of max_staleness.

Returns
Type Description
Google\Protobuf\Duration|null

hasExactStaleness

setExactStaleness

Executes all reads at a timestamp that is exact_staleness old. The timestamp is chosen soon after the read is started.

Guarantees that all writes that have committed more than the specified number of seconds ago are visible. Because Cloud Spanner chooses the exact timestamp, this mode works even if the client's local clock is substantially skewed from Cloud Spanner commit timestamps. Useful for reading at nearby replicas without the distributed timestamp negotiation overhead of max_staleness.

Parameter
Name Description
var Google\Protobuf\Duration
Returns
Type Description
$this

getReturnReadTimestamp

If true, the Cloud Spanner-selected read timestamp is included in the Transaction message that describes the transaction.

Returns
Type Description
bool

setReturnReadTimestamp

If true, the Cloud Spanner-selected read timestamp is included in the Transaction message that describes the transaction.

Parameter
Name Description
var bool
Returns
Type Description
$this

getTimestampBound

Returns
Type Description
string