Class: Google::Apis::SpannerV1::ReadOnly

Inherits:

Object

• Object
• Google::Apis::SpannerV1::ReadOnly

Includes:

Core::Hashable, Core::JsonObjectSupport

Defined in:

lib/google/apis/spanner_v1/classes.rb,
lib/google/apis/spanner_v1/representations.rb,
lib/google/apis/spanner_v1/representations.rb

Overview

Message type to initiate a read-only transaction.

Instance Attribute Summary

• #exact_staleness ⇒ String

  Executes all reads at a timestamp that is exact_staleness old.

• #max_staleness ⇒ String

  Read data at a timestamp >= NOW - max_staleness seconds.

• #min_read_timestamp ⇒ String

  Executes all reads at a timestamp >= min_read_timestamp.

• #read_timestamp ⇒ String

  Executes all reads at the given timestamp.

• #return_read_timestamp ⇒ Boolean (also: #return_read_timestamp?)

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

• #strong ⇒ Boolean (also: #strong?)

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

Instance Method Summary

• #initialize(**args) ⇒ ReadOnly constructor

  A new instance of ReadOnly.

• #update!(**args) ⇒ Object

  Update properties of this object.

Constructor Details

#initialize(**args) ⇒ ReadOnly

Returns a new instance of ReadOnly.

# File 'lib/google/apis/spanner_v1/classes.rb', line 3206

def initialize(**args)
   update!(**args)
end

Instance Attribute Details

#exact_staleness ⇒ String

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. Corresponds to the JSON property exactStaleness

Returns:

• (String)

# File 'lib/google/apis/spanner_v1/classes.rb', line 3159

def exact_staleness
  @exact_staleness
end

#max_staleness ⇒ String

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. Corresponds to the JSON property maxStaleness

Returns:

• (String)

# File 'lib/google/apis/spanner_v1/classes.rb', line 3170

def max_staleness
  @max_staleness
end

#min_read_timestamp ⇒ String

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". Corresponds to the JSON property minReadTimestamp

Returns:

• (String)

# File 'lib/google/apis/spanner_v1/classes.rb', line 3180

def min_read_timestamp
  @min_read_timestamp
end

#read_timestamp ⇒ String

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". Corresponds to the JSON property readTimestamp

Returns:

• (String)

# File 'lib/google/apis/spanner_v1/classes.rb', line 3191

def read_timestamp
  @read_timestamp
end

#return_read_timestamp ⇒ Boolean Also known as: return_read_timestamp?

If true, the Cloud Spanner-selected read timestamp is included in the Transaction message that describes the transaction. Corresponds to the JSON property returnReadTimestamp

Returns:

• (Boolean)

# File 'lib/google/apis/spanner_v1/classes.rb', line 3197

def return_read_timestamp
  @return_read_timestamp
end

#strong ⇒ Boolean Also known as: strong?

Read at a timestamp where all previously committed transactions are visible. Corresponds to the JSON property strong

Returns:

• (Boolean)

# File 'lib/google/apis/spanner_v1/classes.rb', line 3203

def strong
  @strong
end

Instance Method Details

#update!(**args) ⇒ Object

Update properties of this object

# File 'lib/google/apis/spanner_v1/classes.rb', line 3211

def update!(**args)
  @exact_staleness = args[:exact_staleness] if args.key?(:exact_staleness)
  @max_staleness = args[:max_staleness] if args.key?(:max_staleness)
  @min_read_timestamp = args[:min_read_timestamp] if args.key?(:min_read_timestamp)
  @read_timestamp = args[:read_timestamp] if args.key?(:read_timestamp)
  @return_read_timestamp = args[:return_read_timestamp] if args.key?(:return_read_timestamp)
  @strong = args[:strong] if args.key?(:strong)
end