Pinot provides to query database directly from go application.
Install
Follow this link to install and start Pinot locally.
Copy bin/quick-start-batch.sh
Copy git clone git@github.com:startreedata/pinot-client-go.git
cd pinot-client-go
Build and run the example application to query from the .
Copy go build ./examples/batch-quickstart
./batch-quickstart
Use the Golang client
Create a Pinot connection
Initialize the Pinot client using one of the methods below.
Zookeeper Path
Copy pinotClient := pinot.NewFromZookeeper([]string{"localhost:2123"}, "", "QuickStartCluster")
List of broker addresses
Copy pinotClient := pinot.NewFromBrokerList([]string{"localhost:8000"})
ClientConfig
Copy pinotClient := pinot.NewWithConfig(&pinot.ClientConfig{
ZkConfig: &pinot.ZookeeperConfig{
ZookeeperPath: zkPath,
PathPrefix: strings.Join([]string{zkPathPrefix, pinotCluster}, "/"),
SessionTimeoutSec: defaultZkSessionTimeoutSec,
},
ExtraHTTPHeader: map[string]string{
"extra-header":"value",
},
})
Query Pinot
Code snippet:
Copy pinotClient, err := pinot.NewFromZookeeper([]string{"localhost:2123"}, "", "QuickStartCluster")
if err != nil {
log.Error(err)
}
brokerResp, err := pinotClient.ExecuteSQL("baseballStats", "select count(*) as cnt, sum(homeRuns) as sum_homeRuns from baseballStats group by teamID limit 10")
if err != nil {
log.Error(err)
}
log.Infof("Query Stats: response time - %d ms, scanned docs - %d, total docs - %d", brokerResp.TimeUsedMs, brokerResp.NumDocsScanned, brokerResp.TotalDocs)
The query response has the following format:
Copy type BrokerResponse struct {
AggregationResults []*AggregationResult `json:"aggregationResults,omitempty"`
SelectionResults *SelectionResults `json:"SelectionResults,omitempty"`
ResultTable *ResultTable `json:"resultTable,omitempty"`
Exceptions []Exception `json:"exceptions"`
TraceInfo map[string]string `json:"traceInfo,omitempty"`
NumServersQueried int `json:"numServersQueried"`
NumServersResponded int `json:"numServersResponded"`
NumSegmentsQueried int `json:"numSegmentsQueried"`
NumSegmentsProcessed int `json:"numSegmentsProcessed"`
NumSegmentsMatched int `json:"numSegmentsMatched"`
NumConsumingSegmentsQueried int `json:"numConsumingSegmentsQueried"`
NumDocsScanned int64 `json:"numDocsScanned"`
NumEntriesScannedInFilter int64 `json:"numEntriesScannedInFilter"`
NumEntriesScannedPostFilter int64 `json:"numEntriesScannedPostFilter"`
NumGroupsLimitReached bool `json:"numGroupsLimitReached"`
TotalDocs int64 `json:"totalDocs"`
TimeUsedMs int `json:"timeUsedMs"`
MinConsumingFreshnessTimeMs int64 `json:"minConsumingFreshnessTimeMs"`
}
Note that AggregationResults
and SelectionResults
are holders for Pinot query language (PQL) queries.
Meanwhile, ResultTable
is the holder for SQL queries. ResultTable
is defined as:
Copy // ResultTable is a ResultTable
type ResultTable struct {
DataSchema RespSchema `json:"dataSchema"`
Rows [][]interface{} `json:"rows"`
}
RespSchema
is defined as:
Copy // RespSchema is response schema
type RespSchema struct {
ColumnDataTypes []string `json:"columnDataTypes"`
ColumnNames []string `json:"columnNames"`
}
There are multiple functions defined for ResultTable
, such as the following:
Copy func (r ResultTable) GetRowCount() int
func (r ResultTable) GetColumnCount() int
func (r ResultTable) GetColumnName(columnIndex int) string
func (r ResultTable) GetColumnDataType(columnIndex int) string
func (r ResultTable) Get(rowIndex int, columnIndex int) interface{}
func (r ResultTable) GetString(rowIndex int, columnIndex int) string
func (r ResultTable) GetInt(rowIndex int, columnIndex int) int
func (r ResultTable) GetLong(rowIndex int, columnIndex int) int64
func (r ResultTable) GetFloat(rowIndex int, columnIndex int) float32
func (r ResultTable) GetDouble(rowIndex int, columnIndex int) float64
Copy // Print Response Schema
for c := 0; c < brokerResp.ResultTable.GetColumnCount(); c++ {
fmt.Printf("%s(%s)\t", brokerResp.ResultTable.GetColumnName(c), brokerResp.ResultTable.GetColumnDataType(c))
}
fmt.Println()
// Print Row Table
for r := 0; r < brokerResp.ResultTable.GetRowCount(); r++ {
for c := 0; c < brokerResp.ResultTable.GetColumnCount(); c++ {
fmt.Printf("%v\t", brokerResp.ResultTable.Get(r, c))
}
fmt.Println()
}