[fix](stats)min and max return NaN when table is empty (#27862)

fix analyze empty table and min/max null value bug:
1. Skip empty analyze task for sample analyze task. (Full analyze task already skipped).
2. Check sample rows is not 0 before calculate the scale factor.
3. Remove ' in sql template after remove base64 encoding for min/max value.

fe/fe-core/src/main/java/org/apache/doris/statistics/BaseAnalysisTask.java

@@ -92,8 +92,8 @@ public abstract class BaseAnalysisTask {
             + "${rowCount} AS `row_count`, "
             + "${ndvFunction} as `ndv`, "
             + "IFNULL(SUM(IF(`t1`.`column_key` IS NULL, `t1`.`count`, 0)), 0) * ${scaleFactor} as `null_count`, "
-            + "'${min}' AS `min`, "
-            + "'${max}' AS `max`, "
+            + "${min} AS `min`, "
+            + "${max} AS `max`, "
             + "${dataSizeFunction} * ${scaleFactor} AS `data_size`, "
             + "NOW() "
             + "FROM ( "
@@ -115,8 +115,8 @@ public abstract class BaseAnalysisTask {
             + "${row_count} AS `row_count`, "
             + "${ndv} AS `ndv`, "
             + "${null_count} AS `null_count`, "
-            + "'${min}' AS `min`, "
-            + "'${max}' AS `max`, "
+            + "${min} AS `min`, "
+            + "${max} AS `max`, "
             + "${data_size} AS `data_size`, "
             + "NOW() ";
 
@@ -311,7 +311,7 @@ public abstract class BaseAnalysisTask {
         this.job = job;
     }
 
-    protected void runQuery(String sql, boolean needEncode) {
+    protected void runQuery(String sql) {
         long startTime = System.currentTimeMillis();
         try (AutoCloseConnectContext a  = StatisticsUtil.buildConnectContext()) {
             stmtExecutor = new StmtExecutor(a.connectContext, sql);

fe/fe-core/src/main/java/org/apache/doris/statistics/HMSAnalysisTask.java

@@ -159,7 +159,7 @@ public class HMSAnalysisTask extends BaseAnalysisTask {
         }
         stringSubstitutor = new StringSubstitutor(params);
         String sql = stringSubstitutor.replace(sb.toString());
-        runQuery(sql, true);
+        runQuery(sql);
     }
 
     // Collect the partition column stats through HMS metadata.
@@ -201,12 +201,12 @@ public class HMSAnalysisTask extends BaseAnalysisTask {
         params.put("row_count", String.valueOf(count));
         params.put("ndv", String.valueOf(ndv));
         params.put("null_count", String.valueOf(numNulls));
-        params.put("min", min);
-        params.put("max", max);
+        params.put("min", StatisticsUtil.quote(min));
+        params.put("max", StatisticsUtil.quote(max));
         params.put("data_size", String.valueOf(dataSize));
         StringSubstitutor stringSubstitutor = new StringSubstitutor(params);
         String sql = stringSubstitutor.replace(ANALYZE_PARTITION_COLUMN_TEMPLATE);
-        runQuery(sql, true);
+        runQuery(sql);
     }
 
     private String updateMinValue(String currentMin, String value) {
@@ -313,6 +313,9 @@ public class HMSAnalysisTask extends BaseAnalysisTask {
         for (long size : chunkSizes) {
             total += size;
         }
+        if (total == 0) {
+            return Pair.of(1.0, 0L);
+        }
         // Calculate the sample target size for percent and rows sample.
         if (tableSample.isPercent()) {
             target = total * tableSample.getSampleValue() / 100;

fe/fe-core/src/main/java/org/apache/doris/statistics/JdbcAnalysisTask.java

@@ -110,7 +110,7 @@ public class JdbcAnalysisTask extends BaseAnalysisTask {
         params.put("dataSizeFunction", getDataSizeFunction(col, false));
         StringSubstitutor stringSubstitutor = new StringSubstitutor(params);
         String sql = stringSubstitutor.replace(sb.toString());
-        runQuery(sql, true);
+        runQuery(sql);
     }
 
     private Map<String, String> buildTableStatsParams(String partId) {

fe/fe-core/src/main/java/org/apache/doris/statistics/OlapAnalysisTask.java

@@ -59,7 +59,13 @@ public class OlapAnalysisTask extends BaseAnalysisTask {
     }
 
     public void doExecute() throws Exception {
-
+        Set<String> partitionNames = info.colToPartitions.get(info.colName);
+        if (partitionNames.isEmpty()) {
+            LOG.debug("Skip empty empty partition task for column {} in {}.{}.{}",
+                    info.catalogId, info.dbId, info.tblId, info.colName);
+            job.appendBuf(this, Collections.emptyList());
+            return;
+        }
         if (tableSample != null) {
             doSample();
         } else {
@@ -113,24 +119,25 @@ public class OlapAnalysisTask extends BaseAnalysisTask {
             params.put("scaleFactor", String.valueOf(scaleFactor));
             params.put("sampleHints", tabletStr.isEmpty() ? "" : String.format("TABLET(%s)", tabletStr));
             params.put("ndvFunction", getNdvFunction(String.valueOf(rowCount)));
-            params.put("min", min);
-            params.put("max", max);
+            params.put("min", StatisticsUtil.quote(min));
+            params.put("max", StatisticsUtil.quote(max));
             params.put("rowCount", String.valueOf(rowCount));
             params.put("type", col.getType().toString());
             params.put("limit", "");
             if (needLimit()) {
                 // If the tablets to be sampled are too large, use limit to control the rows to read, and re-calculate
                 // the scaleFactor.
-                limitFlag = true;
                 rowsToSample = Math.min(getSampleRows(), pair.second);
-                params.put("limit", "limit " + rowsToSample);
-                params.put("scaleFactor", String.valueOf(scaleFactor * (double) pair.second / rowsToSample));
+                // Empty table doesn't need to limit.
+                if (rowsToSample > 0) {
+                    limitFlag = true;
+                    params.put("limit", "limit " + rowsToSample);
+                    params.put("scaleFactor", String.valueOf(scaleFactor * (double) pair.second / rowsToSample));
+                }
             }
             StringSubstitutor stringSubstitutor = new StringSubstitutor(params);
             String sql;
             if (useLinearAnalyzeTemplate()) {
-                params.put("min", StatisticsUtil.quote(min));
-                params.put("max", StatisticsUtil.quote(max));
                 // For single unique key, use count as ndv.
                 if (isSingleUniqueKey()) {
                     params.put("ndvFunction", String.valueOf(rowCount));
@@ -148,7 +155,7 @@ public class OlapAnalysisTask extends BaseAnalysisTask {
                     col.getName(), params.get("rowCount"), rowsToSample, params.get("scaleFactor"),
                     limitFlag, tbl.isDistributionColumn(col.getName()),
                     tbl.isPartitionColumn(col.getName()), col.isKey(), isSingleUniqueKey());
-            runQuery(sql, false);
+            runQuery(sql);
         }
     }
 
@@ -169,11 +176,6 @@ public class OlapAnalysisTask extends BaseAnalysisTask {
      */
     protected void doFull() throws Exception {
         LOG.debug("Will do full collection for column {}", col.getName());
-        Set<String> partitionNames = info.colToPartitions.get(info.colName);
-        if (partitionNames.isEmpty()) {
-            job.appendBuf(this, Collections.emptyList());
-            return;
-        }
         Map<String, String> params = new HashMap<>();
         params.put("internalDB", FeConstants.INTERNAL_DB_NAME);
         params.put("columnStatTbl", StatisticConstants.STATISTIC_TBL_NAME);
@@ -189,7 +191,7 @@ public class OlapAnalysisTask extends BaseAnalysisTask {
         params.put("tblName", String.valueOf(tbl.getName()));
         StringSubstitutor stringSubstitutor = new StringSubstitutor(params);
         String collectColStats = stringSubstitutor.replace(COLLECT_COL_STATISTICS);
-        runQuery(collectColStats, true);
+        runQuery(collectColStats);
     }
 
     // Get sample tablets id and scale up scaleFactor