ES|QL - kNN function initial support

server/src/main/java/org/elasticsearch/index/mapper/vectors/DenseVectorFieldMapper.java

@@ -2577,6 +2577,11 @@ public BlockLoader blockLoader(MappedFieldType.BlockLoaderContext blContext) {
                 return null;
             }
 
+            if (dims == null) {
+                // No data has been indexed yet
+                return BlockLoader.CONSTANT_NULLS;
+            }
+
             if (indexed) {
                 return new BlockDocValuesReader.DenseVectorBlockLoader(name(), dims);
             }

x-pack/plugin/esql/compute/src/main/java/org/elasticsearch/compute/lucene/LuceneQueryEvaluator.java

@@ -112,7 +112,7 @@ private Vector evalSingleSegmentNonDecreasing(DocVector docs) throws IOException
         int min = docs.docs().getInt(0);
         int max = docs.docs().getInt(docs.getPositionCount() - 1);
         int length = max - min + 1;
-        try (T scoreBuilder = createVectorBuilder(blockFactory, length)) {
+        try (T scoreBuilder = createVectorBuilder(blockFactory, docs.getPositionCount())) {
             if (length == docs.getPositionCount() && length > 1) {
                 return segmentState.scoreDense(scoreBuilder, min, max);
             }

x-pack/plugin/esql/qa/server/src/main/java/org/elasticsearch/xpack/esql/qa/rest/RestEsqlTestCase.java

@@ -1022,7 +1022,7 @@ public void testMultipleBatchesWithLookupJoin() throws IOException {
             var query = requestObjectBuilder().query(format(null, "from * | lookup join {} on integer {}", testIndexName(), sort));
             Map<String, Object> result = runEsql(query);
             var columns = as(result.get("columns"), List.class);
-            assertEquals(21, columns.size());
+            assertEquals(22, columns.size());
             var values = as(result.get("values"), List.class);
             assertEquals(10, values.size());
         }

x-pack/plugin/esql/qa/testFixtures/src/main/java/org/elasticsearch/xpack/esql/CsvTestsDataLoader.java

@@ -144,6 +144,7 @@ public class CsvTestsDataLoader {
     private static final TestDataset LOGS = new TestDataset("logs");
     private static final TestDataset MV_TEXT = new TestDataset("mv_text");
     private static final TestDataset DENSE_VECTOR = new TestDataset("dense_vector");
+    private static final TestDataset COLORS = new TestDataset("colors");
 
     public static final Map<String, TestDataset> CSV_DATASET_MAP = Map.ofEntries(
         Map.entry(EMPLOYEES.indexName, EMPLOYEES),
@@ -204,7 +205,8 @@ public class CsvTestsDataLoader {
         Map.entry(SEMANTIC_TEXT.indexName, SEMANTIC_TEXT),
         Map.entry(LOGS.indexName, LOGS),
         Map.entry(MV_TEXT.indexName, MV_TEXT),
-        Map.entry(DENSE_VECTOR.indexName, DENSE_VECTOR)
+        Map.entry(DENSE_VECTOR.indexName, DENSE_VECTOR),
+        Map.entry(COLORS.indexName, COLORS)
     );
 
     private static final EnrichConfig LANGUAGES_ENRICH = new EnrichConfig("languages_policy", "enrich-policy-languages.json");

x-pack/plugin/esql/qa/testFixtures/src/main/resources/data/colors.csv

@@ -0,0 +1,139 @@
+color:text,hex_code:keyword,rgb_vector:dense_vector,primary:boolean
+maroon, #800000, [128,0,0], false
+dark red, #8B0000, [139,0,0], false
+brown, #A52A2A, [165,42,42], false
+firebrick, #B22222, [178,34,34], false
+crimson, #DC143C, [220,20,60], false
+red, #FF0000, [255,0,0], true
+tomato, #FF6347, [255,99,71], false
+coral, #FF7F50, [255,127,80], false
+indian red, #CD5C5C, [205,92,92], false
+light coral, #F08080, [240,128,128], false
+dark salmon, #E9967A, [233,150,122], false
+salmon, #FA8072, [250,128,114], false
+light salmon, #FFA07A, [255,160,122], false
+orange red, #FF4500, [255,69,0], false
+dark orange, #FF8C00, [255,140,0], false
+orange, #FFA500, [255,165,0], false
+gold, #FFD700, [255,215,0], false
+dark golden rod, #B8860B, [184,134,11], false
+golden rod, #DAA520, [218,165,32], false
+pale golden rod, #EEE8AA, [238,232,170], false
+dark khaki, #BDB76B, [189,183,107], false
+khaki, #F0E68C, [240,230,140], false
+olive, #808000, [128,128,0], false
+yellow, #FFFF00, [255,255,0], true
+yellow green, #9ACD32, [154,205,50], false
+dark olive green, #556B2F, [85,107,47], false
+olive drab, #6B8E23, [107,142,35], false
+lawn green, #7CFC00, [124,252,0], false
+chartreuse, #7FFF00, [127,255,0], false
+green yellow, #ADFF2F, [173,255,47], false
+dark green, #006400, [0,100,0], false
+green, #008000, [0,128,0], true
+forest green, #228B22, [34,139,34], false
+lime, #00FF00, [0,255,0], false
+lime green, #32CD32, [50,205,50], false
+light green, #90EE90, [144,238,144], false
+pale green, #98FB98, [152,251,152], false
+dark sea green, #8FBC8F, [143,188,143], false
+medium spring green, #00FA9A, [0,250,154], false
+spring green, #00FF7F, [0,255,127], false
+sea green, #2E8B57, [46,139,87], false
+medium aqua marine, #66CDAA, [102,205,170], false
+medium sea green, #3CB371, [60,179,113], false
+light sea green, #20B2AA, [32,178,170], false
+dark slate gray, #2F4F4F, [47,79,79], false
+teal, #008080, [0,128,128], false
+dark cyan, #008B8B, [0,139,139], false
+cyan, #00FFFF, [0,255,255], true
+light cyan, #E0FFFF, [224,255,255], false
+dark turquoise, #00CED1, [0,206,209], false
+turquoise, #40E0D0, [64,224,208], false
+medium turquoise, #48D1CC, [72,209,204], false
+pale turquoise, #AFEEEE, [175,238,238], false
+aqua marine, #7FFFD4, [127,255,212], false
+powder blue, #B0E0E6, [176,224,230], false
+cadet blue, #5F9EA0, [95,158,160], false
+steel blue, #4682B4, [70,130,180], false
+corn flower blue, #6495ED, [100,149,237], false
+deep sky blue, #00BFFF, [0,191,255], false
+dodger blue, #1E90FF, [30,144,255], false
+light blue, #ADD8E6, [173,216,230], false
+sky blue, #87CEEB, [135,206,235], false
+light sky blue, #87CEFA, [135,206,250], false
+midnight blue, #191970, [25,25,112], false
+navy, #000080, [0,0,128], false
+dark blue, #00008B, [0,0,139], false
+medium blue, #0000CD, [0,0,205], false
+blue, #0000FF, [0,0,255], true
+royal blue, #4169E1, [65,105,225], false
+blue violet, #8A2BE2, [138,43,226], false
+indigo, #4B0082, [75,0,130], false
+dark slate blue, #483D8B, [72,61,139], false
+slate blue, #6A5ACD, [106,90,205], false
+medium slate blue, #7B68EE, [123,104,238], false
+medium purple, #9370DB, [147,112,219], false
+dark magenta, #8B008B, [139,0,139], false
+dark violet, #9400D3, [148,0,211], false
+dark orchid, #9932CC, [153,50,204], false
+medium orchid, #BA55D3, [186,85,211], false
+purple, #800080, [128,0,128], false
+thistle, #D8BFD8, [216,191,216], false
+plum, #DDA0DD, [221,160,221], false
+violet, #EE82EE, [238,130,238], false
+magenta, #FF00FF, [255,0,255], true
+orchid, #DA70D6, [218,112,214], false
+medium violet red, #C71585, [199,21,133], false
+pale violet red, #DB7093, [219,112,147], false
+deep pink, #FF1493, [255,20,147], false
+hot pink, #FF69B4, [255,105,180], false
+light pink, #FFB6C1, [255,182,193], false
+pink, #FFC0CB, [255,192,203], false
+antique white, #FAEBD7, [250,235,215], false
+beige, #F5F5DC, [245,245,220], false
+bisque, #FFE4C4, [255,228,196], false
+blanched almond, #FFEBCD, [255,235,205], false
+wheat, #F5DEB3, [245,222,179], false
+corn silk, #FFF8DC, [255,248,220], false
+lemon chiffon, #FFFACD, [255,250,205], false
+light golden rod yellow, #FAFAD2, [250,250,210], false
+light yellow, #FFFFE0, [255,255,224], false
+saddle brown, #8B4513, [139,69,19], false
+sienna, #A0522D, [160,82,45], false
+chocolate, #D2691E, [210,105,30], false
+peru, #CD853F, [205,133,63], false
+sandy brown, #F4A460, [244,164,96], false
+burly wood, #DEB887, [222,184,135], false
+tan, #D2B48C, [210,180,140], false
+rosy brown, #BC8F8F, [188,143,143], false
+moccasin, #FFE4B5, [255,228,181], false
+navajo white, #FFDEAD, [255,222,173], false
+peach puff, #FFDAB9, [255,218,185], false
+misty rose, #FFE4E1, [255,228,225], false
+lavender blush, #FFF0F5, [255,240,245], false
+linen, #FAF0E6, [250,240,230], false
+old lace, #FDF5E6, [253,245,230], false
+papaya whip, #FFEFD5, [255,239,213], false
+sea shell, #FFF5EE, [255,245,238], false
+mint cream, #F5FFFA, [245,255,250], false
+slate gray, #708090, [112,128,144], false
+light slate gray, #778899, [119,136,153], false
+light steel blue, #B0C4DE, [176,196,222], false
+lavender, #E6E6FA, [230,230,250], false
+floral white, #FFFAF0, [255,250,240], false
+alice blue, #F0F8FF, [240,248,255], false
+ghost white, #F8F8FF, [248,248,255], false
+honeydew, #F0FFF0, [240,255,240], false
+ivory, #FFFFF0, [255,255,240], false
+azure, #F0FFFF, [240,255,255], false
+snow, #FFFAFA, [255,250,250], false
+black, #000000, [0,0,0], true
+dim gray, #696969, [105,105,105], false
+gray, #808080, [128,128,128], true
+dark gray, #A9A9A9, [169,169,169], false
+silver, #C0C0C0, [192,192,192], false
+light gray, #D3D3D3, [211,211,211], false
+gainsboro, #DCDCDC, [220,220,220], false
+white smoke, #F5F5F5, [245,245,245], false
+white, #FFFFFF, [255,255,255], true