in-memory parts: test for basic functionality

tests/queries/0_stateless/01130_in_memory_parts.reference

@@ -0,0 +1,27 @@
+Simple selects
+0	0
+1	1
+2	2
+3	0
+4	1
+50	2
+51	0
+52	1
+53	2
+54	0
+34
+0
+Mutations and Alters
+66
+1	1
+2	2
+4	1
+5	2
+7	1
+[1,1]
+[]
+[4,16]
+[]
+[7,49]
+1	1
+2	1

tests/queries/0_stateless/01130_in_memory_parts.sql

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+DROP TABLE IF EXISTS in_memory;
+CREATE TABLE in_memory (a UInt32, b UInt32)
+    ENGINE = MergeTree ORDER BY a
+    SETTINGS min_rows_for_compact_part = 0;
+
+INSERT INTO in_memory SELECT number, number % 3 FROM numbers(100);
+
+SELECT 'Simple selects';
+
+SELECT * FROM in_memory ORDER BY a LIMIT 5;
+SELECT * FROM in_memory ORDER BY a LIMIT 5 OFFSET 50;
+SELECT count() FROM in_memory WHERE b = 0 SETTINGS max_block_size = 10;
+-- Check index
+SELECT count() FROM in_memory WHERE a > 100 SETTINGS max_rows_to_read = 0, force_primary_key = 1;
+
+SELECT 'Mutations and Alters';
+SET mutations_sync = 1;
+
+ALTER TABLE in_memory DELETE WHERE b = 0;
+
+SELECT count() FROM in_memory;
+SELECT * FROM in_memory ORDER BY a LIMIT 5;
+
+ALTER TABLE in_memory ADD COLUMN arr Array(UInt64);
+ALTER TABLE in_memory UPDATE arr = [a, a * a] WHERE b = 1;
+
+SELECT arr FROM in_memory ORDER BY a LIMIT 5;
+
+ALTER TABLE in_memory MODIFY COLUMN b String;
+ALTER TABLE in_memory RENAME COLUMN b to str;
+SELECT DISTINCT str, length(str) FROM in_memory ORDER BY str;
+
+DROP TABLE in_memory;