Returning JobId as result

src/backend/distributed/operations/auto_shard_split.c

@@ -13,6 +13,7 @@
 #include "utils/lsyscache.h"
 #include "distributed/listutils.h"
 #include "distributed/metadata_utility.h"
+#include "distributed/background_jobs.h"
 
 PG_FUNCTION_INFO_V1(citus_auto_shard_split_start);
 
@@ -44,9 +45,9 @@ StringInfo GetShardSplitQuery(ShardInfo shardinfo, List *splitPoints,
 							  char *shardSplitMode);
 void ExecuteSplitBackgroundJob(int64 jobId, ShardInfo shardinfo, List *splitPoints,
 							   char *shardSplitMode);
-int64 ExecuteAvgHashQuery(ShardInfo shardinfo);
+int64 ExecuteAverageHashQuery(ShardInfo shardinfo);
 List * FindShardSplitPoints(ShardInfo shardinfo);
-void ScheduleShardSplit(ShardInfo shardinfo, char *shardSplitMode);
+int64 ScheduleShardSplit(ShardInfo shardinfo, char *shardSplitMode , int64 jobId);
 
 /*
  * It throws an error if a concurrent automatic shard split or Rebalance operation is happening.
@@ -87,7 +88,7 @@ GetShardSplitQuery(ShardInfo shardinfo, List *splitPoints, char *shardSplitMode)
 					 shardinfo->shardId);
 
 	int32 splitpoint = 0;
-	int index = 0;
+	uint64 index = 0;
 	foreach_int(splitpoint, splitPoints)
 	{
 		appendStringInfo(splitQuery, "'%d'", splitpoint);
@@ -136,7 +137,7 @@ ExecuteSplitBackgroundJob(int64 jobId, ShardInfo shardinfo, List *splitPoints,
  * If there exists a hash value it is returned otherwise shardminvalue-1 is returned.
  */
 int64
-ExecuteAvgHashQuery(ShardInfo shardinfo)
+ExecuteAverageHashQuery(ShardInfo shardinfo)
 {
 	StringInfo AvgHashQuery = makeStringInfo();
 	uint64 tableSize = 0;
@@ -150,7 +151,7 @@ ExecuteAvgHashQuery(ShardInfo shardinfo)
 					 shardinfo->distributionColumn, shardinfo->shardMinValue,
 					 shardinfo->distributionColumn, shardinfo->shardMaxValue
 					 );
-	ereport(LOG, errmsg("%s", AvgHashQuery->data));
+	ereport(DEBUG4, errmsg("%s", AvgHashQuery->data));
 	SPI_connect();
 	SPI_exec(AvgHashQuery->data, 0);
 	SPITupleTable *tupletable = SPI_tuptable;
@@ -193,7 +194,7 @@ FindShardSplitPoints(ShardInfo shardinfo)
 	appendStringInfo(CommonValueQuery,
 					 "SELECT shardid , unnest(result::%s[]) from run_command_on_shards(%s,$$SELECT array_agg(val)"
 					 " FROM pg_stats s , unnest(most_common_vals::text::%s[],most_common_freqs) as res(val,freq)"
-					 " WHERE tablename = %s AND attname = %s AND schemaname = %s AND freq > %f $$)"
+					 " WHERE tablename = %s AND attname = %s AND schemaname = %s AND freq > %lf $$)"
 					 " WHERE result <> '' AND shardid = %ld;",
 					 shardinfo->dataType, quote_literal_cstr(shardinfo->tableName),
 					 shardinfo->dataType,
@@ -204,7 +205,7 @@ FindShardSplitPoints(ShardInfo shardinfo)
 					 TenantFrequency,
 					 shardinfo->shardId);
 
-	ereport(LOG, errmsg("%s", CommonValueQuery->data));
+	ereport(DEBUG4, errmsg("%s", CommonValueQuery->data));
 	List *splitPoints = NULL;
 
 	/* Saving the current memory context*/
@@ -220,17 +221,21 @@ FindShardSplitPoints(ShardInfo shardinfo)
 	int64 average;
 	int32 hashedValue;
 
-	ereport(LOG, errmsg("%ld", rowCount));
+	ereport(DEBUG4, errmsg("%ld", rowCount));
 
 	if (rowCount > 0)
 	{
+		/*For every common tenant value split point is calculated on the basis of 
+		 * the hashed value and the unique split points are appended to the list
+		 * and the resulting is then sorted and returned.
+		*/
 		SPITupleTable *tupletable = SPI_tuptable;
 		CitusTableCacheEntry *cacheEntry = GetCitusTableCacheEntry(shardinfo->tableId);
 		for (int rowIndex = 0; rowIndex < rowCount; rowIndex++)
 		{
 			HeapTuple tuple = tupletable->vals[rowIndex];
 			char *commonValue = SPI_getvalue(tuple, tupletable->tupdesc, 2);
-			ereport(LOG, errmsg("%s", commonValue));
+			ereport(DEBUG4, errmsg("%s", commonValue));
 			Datum tenantIdDatum = StringToDatum(commonValue,
 												shardinfo->distributionColumnId);
 			Datum hashedValueDatum = FunctionCall1Coll(cacheEntry->hashFunction,
@@ -238,7 +243,7 @@ FindShardSplitPoints(ShardInfo shardinfo)
 													   varcollid,
 													   tenantIdDatum);
 			hashedValue = DatumGetInt32(hashedValueDatum);
-			ereport(LOG, errmsg("%d", hashedValue));
+			ereport(DEBUG4, errmsg("%d", hashedValue));
 
 			/*Switching the memory context to store the unique SplitPoints in a list*/
 
@@ -263,8 +268,8 @@ FindShardSplitPoints(ShardInfo shardinfo)
 	}
 	else
 	{
-		average = ExecuteAvgHashQuery(shardinfo);
-		ereport(LOG, errmsg("%ld", average));
+		average = ExecuteAverageHashQuery(shardinfo);
+		ereport(DEBUG4, errmsg("%ld", average));
 		MemoryContextSwitchTo(originalContext);
 		if (shardinfo->shardMinValue <= average)
 		{
@@ -281,21 +286,21 @@ FindShardSplitPoints(ShardInfo shardinfo)
  * This function calculates the split points of the shard to
  * split and then executes the background job for the shard split.
  */
-void
-ScheduleShardSplit(ShardInfo shardinfo, char *shardSplitMode)
+int64
+ScheduleShardSplit(ShardInfo shardinfo, char *shardSplitMode , int64 jobId)
 {
 	List *splitPoints = FindShardSplitPoints(shardinfo);
 	if (list_length(splitPoints) > 0)
 	{
-		int64 jobId = CreateBackgroundJob("Automatic Shard Split",
-										  "Split using SplitPoints List");
-		ereport(LOG, errmsg("%s", GetShardSplitQuery(shardinfo, splitPoints,
+		ereport(DEBUG4, errmsg("%s", GetShardSplitQuery(shardinfo, splitPoints,
 													 shardSplitMode)->data));
 		ExecuteSplitBackgroundJob(jobId, shardinfo, splitPoints, shardSplitMode);
+		return 1;
 	}
 	else
 	{
 		ereport(LOG, errmsg("No Splitpoints for shard split"));
+		return 0;
 	}
 }
 
@@ -328,11 +333,11 @@ citus_auto_shard_split_start(PG_FUNCTION_ARGS)
 		MaxShardSize*1024
 		);
 
-	ereport(LOG, errmsg("%s", query->data));
+	ereport(DEBUG4 ,errmsg("%s", query->data));
 	Oid shardTransferModeOid = PG_GETARG_OID(0);
 	Datum enumLabelDatum = DirectFunctionCall1(enum_out, shardTransferModeOid);
 	char *shardSplitMode = DatumGetCString(enumLabelDatum);
-	ereport(LOG, errmsg("%s", shardSplitMode));
+	ereport(DEBUG4, errmsg("%s", shardSplitMode));
 	if (SPI_connect() != SPI_OK_CONNECT)
 	{
 		elog(ERROR, "SPI_connect to the query failed");
@@ -345,6 +350,9 @@ citus_auto_shard_split_start(PG_FUNCTION_ARGS)
 	SPITupleTable *tupletable = SPI_tuptable;
 	int rowCount = SPI_processed;
 	bool isnull;
+	int64 jobId = CreateBackgroundJob("Automatic Shard Split",
+										  "Split using SplitPoints List");
+	int64 count = 0;
 
 	for (int rowIndex = 0; rowIndex < rowCount; rowIndex++)
 	{
@@ -380,8 +388,8 @@ citus_auto_shard_split_start(PG_FUNCTION_ARGS)
 			distributionColumn);
 		shardinfo.dataType = format_type_be(shardinfo.distributionColumnId);
 
-		ScheduleShardSplit(&shardinfo, shardSplitMode);
-		ereport(LOG, (errmsg(
+		count = count + ScheduleShardSplit(&shardinfo, shardSplitMode , jobId);
+		ereport(DEBUG4, (errmsg(
 						  "Shard ID: %ld,ShardMinValue: %ld, ShardMaxValue: %ld , totalSize: %ld , nodeId: %d",
 						  shardinfo.shardId, shardinfo.shardMinValue,
 						  shardinfo.shardMaxValue,
@@ -390,6 +398,9 @@ citus_auto_shard_split_start(PG_FUNCTION_ARGS)
 
 	SPI_freetuptable(tupletable);
 	SPI_finish();
-
-	PG_RETURN_VOID();
+	if(count==0){
+		DirectFunctionCall1(citus_job_cancel, Int64GetDatum(jobId));
+	}
+
+	PG_RETURN_INT64(jobId);
 }

src/backend/distributed/sql/udfs/citus_auto_shard_split_start/12.0-1.sql

@@ -2,7 +2,7 @@ CREATE OR REPLACE FUNCTION pg_catalog.citus_auto_shard_split_start(
     shard_transfer_mode citus.shard_transfer_mode default 'auto'
 
     )
-    RETURNS VOID
+    RETURNS bigint
 
     AS 'MODULE_PATHNAME'
 

src/backend/distributed/sql/udfs/citus_auto_shard_split_start/latest.sql

@@ -2,7 +2,7 @@ CREATE OR REPLACE FUNCTION pg_catalog.citus_auto_shard_split_start(
     shard_transfer_mode citus.shard_transfer_mode default 'auto'
 
     )
-    RETURNS VOID
+    RETURNS bigint
 
     AS 'MODULE_PATHNAME'