ReadOnly class
Message type to initiate a read-only transaction.
Constructors
- ReadOnly()
- ReadOnly.fromJson(Map _json)
Properties
- exactStaleness ↔ 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 ofmax_staleness
.read / write - hashCode → int
-
The hash code for this object. [...]
read-only, inherited
- maxStaleness ↔ 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.read / write - minReadTimestamp ↔ 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"
.read / write - readTimestamp ↔ 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"
.read / write - returnReadTimestamp ↔ bool
-
If true, the Cloud Spanner-selected read timestamp is included in the
Transaction message that describes the transaction.
read / write
- runtimeType → Type
-
A representation of the runtime type of the object.
read-only, inherited
- strong ↔ bool
-
Read at a timestamp where all previously committed transactions are
visible.
read / write
Methods
-
noSuchMethod(
Invocation invocation) → dynamic -
Invoked when a non-existent method or property is accessed. [...]
inherited
-
toJson(
) → Map< String, Object> -
toString(
) → String -
Returns a string representation of this object.
inherited
Operators
-
operator ==(
Object other) → bool -
The equality operator. [...]
inherited