TransactionOptions

Options for beginning a new transaction.

Transactions can be created explicitly with calls to Datastore.BeginTransaction or implicitly by setting ReadOptions.new_transaction in read requests.

JSON representation 
{

  // Union field mode can be only one of the following:
  "readWrite": {
    object (ReadWrite)
  },
  "readOnly": {
    object (ReadOnly)
  }
  // End of list of possible types for union field mode.
}
Fields
Union field mode. The mode of the transaction, indicating whether write operations are supported. mode can be only one of the following:
readWrite

object (ReadWrite)

The transaction should allow both reads and writes.
readOnly

object (ReadOnly)

The transaction should only allow reads.

ReadWrite

Options specific to read / write transactions.

JSON representation 
{
  "previousTransaction": string
}
Fields
previousTransaction

string (bytes format)

The transaction identifier of the transaction being retried.

A base64-encoded string.

ReadOnly

Options specific to read-only transactions.

JSON representation 
{
  "readTime": string
}
Fields
readTime

string (Timestamp format)

Reads entities at the given time.

This must be a microsecond precision timestamp within the past one hour, or if Point-in-Time Recovery is enabled, can additionally be a whole minute timestamp within the past 7 days.

Uses RFC 3339, where generated output will always be Z-normalized and uses 0, 3, 6 or 9 fractional digits. Offsets other than "Z" are also accepted.Examples: "2014-10-02T15:01:23Z", "2014-10-02T15:01:23.045123456Z" or "2014-10-02T15:01:23+05:30".