Class PartialResultSet
Partial results from a streaming read or SQL query. Streaming reads and SQL queries better tolerate large result sets, large rows, and large values, but are a little trickier to consume.
Implements
Inherited Members
Namespace: Google.Apis.Spanner.v1.Data
Assembly: Google.Apis.Spanner.v1.dll
Syntax
public class PartialResultSet : IDirectResponseSchema
Properties
ChunkedValue
If true, then the final value in values is chunked, and must be combined with more values from subsequent
PartialResultSet
s to obtain a complete field value.
Declaration
[JsonProperty("chunkedValue")]
public virtual bool? ChunkedValue { get; set; }
Property Value
Type | Description |
---|---|
bool? |
ETag
The ETag of the item.
Declaration
public virtual string ETag { get; set; }
Property Value
Type | Description |
---|---|
string |
Last
Optional. Indicates whether this is the last PartialResultSet
in the stream. The server might optionally
set this field. Clients shouldn't rely on this field being set in all cases.
Declaration
[JsonProperty("last")]
public virtual bool? Last { get; set; }
Property Value
Type | Description |
---|---|
bool? |
Metadata
Metadata about the result set, such as row type information. Only present in the first response.
Declaration
[JsonProperty("metadata")]
public virtual ResultSetMetadata Metadata { get; set; }
Property Value
Type | Description |
---|---|
ResultSetMetadata |
PrecommitToken
Optional. A precommit token is included if the read-write transaction has multiplexed sessions enabled. Pass the precommit token with the highest sequence number from this transaction attempt to the Commit request for this transaction.
Declaration
[JsonProperty("precommitToken")]
public virtual MultiplexedSessionPrecommitToken PrecommitToken { get; set; }
Property Value
Type | Description |
---|---|
MultiplexedSessionPrecommitToken |
ResumeToken
Streaming calls might be interrupted for a variety of reasons, such as TCP connection loss. If this occurs,
the stream of results can be resumed by re-sending the original request and including resume_token
. Note
that executing any other transaction in the same session invalidates the token.
Declaration
[JsonProperty("resumeToken")]
public virtual string ResumeToken { get; set; }
Property Value
Type | Description |
---|---|
string |
Stats
Query plan and execution statistics for the statement that produced this streaming result set. These can be requested by setting ExecuteSqlRequest.query_mode and are sent only once with the last response in the stream. This field is also present in the last response for DML statements.
Declaration
[JsonProperty("stats")]
public virtual ResultSetStats Stats { get; set; }
Property Value
Type | Description |
---|---|
ResultSetStats |
Values
A streamed result set consists of a stream of values, which might be split into many PartialResultSet
messages to accommodate large rows and/or large values. Every N complete values defines a row, where N is
equal to the number of entries in metadata.row_type.fields. Most values are encoded based on type as
described here. It's possible that the last value in values is "chunked", meaning that the rest of the value
is sent in subsequent PartialResultSet
(s). This is denoted by the chunked_value field. Two or more chunked
values can be merged to form a complete value as follows: * bool/number/null
: can't be chunked * string
:
concatenate the strings * list
: concatenate the lists. If the last element in a list is a string
,
list
, or object
, merge it with the first element in the next list by applying these rules recursively. *
object
: concatenate the (field name, field value) pairs. If a field name is duplicated, then apply these
rules recursively to merge the field values. Some examples of merging: Strings are concatenated. "foo",
"bar" => "foobar" Lists of non-strings are concatenated. [2, 3], [4] => [2, 3, 4] Lists are
concatenated, but the last and first elements are merged because they are strings. ["a", "b"], ["c", "d"]
=> ["a", "bc", "d"] Lists are concatenated, but the last and first elements are merged because they
are lists. Recursively, the last and first elements of the inner lists are merged because they are strings.
["a", ["b", "c"]], [["d"], "e"] => ["a", ["b", "cd"], "e"] Non-overlapping object fields are
combined. {"a": "1"}, {"b": "2"} => {"a": "1", "b": 2"} Overlapping object fields are merged. {"a":
"1"}, {"a": "2"} => {"a": "12"} Examples of merging objects containing lists of strings. {"a":
["1"]}, {"a": ["2"]} => {"a": ["12"]} For a more complete example, suppose a streaming SQL query is
yielding a result set whose rows contain a single string field. The following PartialResultSet
s might be
yielded: { "metadata": { ... } "values": ["Hello", "W"] "chunked_value": true "resume_token": "Af65..." } {
"values": ["orl"] "chunked_value": true } { "values": ["d"] "resume_token": "Zx1B..." } This sequence of
PartialResultSet
s encodes two rows, one containing the field value "Hello"
, and a second containing the
field value "World" = "W" + "orl" + "d"
. Not all PartialResultSet
s contain a resume_token
. Execution
can only be resumed from a previously yielded resume_token
. For the above sequence of PartialResultSet
s,
resuming the query with "resume_token": "Af65..."
yields results from the PartialResultSet
with value
"orl".
Declaration
[JsonProperty("values")]
public virtual IList<object> Values { get; set; }
Property Value
Type | Description |
---|---|
IList<object> |