test DetectDepthRange corner cases

Author: mlin

src/genomicsqlite.cc

@@ -517,7 +517,7 @@ static gri_depth_range_t DetectDepthRange(sqlite3 *dbconn, const string &schema_
     //
     // We'd like to write simply SELECT MIN(_gri_bin), MAX(_gri_bin) ... and trust SQLite to plan
     // an efficient skip-scan of the GRI on (_gri_rid, _gri_bin, ...). Unfortunately it doesn't do
-    // that, so instead we write some convoluted SQL that forces the efficient plan.
+    // that, so instead we write convoluted SQL that forces the efficient plan.
     //
     // This consists of --
     // (i) recursive CTE to find the set of relevant _gri_rid (because even
@@ -544,7 +544,7 @@ static gri_depth_range_t DetectDepthRange(sqlite3 *dbconn, const string &schema_
         tbl_gri +
         " WHERE _gri_rid = __rid AND _gri_bin >= 0 ORDER BY _gri_rid DESC, _gri_bin DESC LIMIT 1)\n"
         "FROM __distinct";
-    _DBG << endl << query << endl;
+    //_DBG << endl << query << endl;
     shared_ptr<sqlite3_stmt> stmt;
     {
         sqlite3_stmt *pStmt = nullptr;

test/test_gri.py

@@ -110,6 +110,85 @@ def test_indexing():
         genomicsqlite.genomic_range_rowids_sql(con, "nonexistent_table")
 
 
+def test_depth_detection():
+    # test corner cases for the bit of genomic_range_rowids() which detects the depth range
+
+    con = sqlite3.connect(":memory:")
+    con.executescript("CREATE TABLE features(rid INTEGER, beg INTEGER, end INTEGER)")
+    con.executescript(
+        genomicsqlite.create_genomic_range_index_sql(con, "features", "rid", "beg", "end")
+    )
+
+    def fanout(query):
+        return sum(
+            1
+            for expl in con.execute("EXPLAIN QUERY PLAN " + query, (None, None, None))
+            if "((_gri_rid,_gri_bin)>(?,?) AND (_gri_rid,_gri_bin)<(?,?))" in expl[3]
+        )
+
+    assert fanout(genomicsqlite.genomic_range_rowids_sql(con, "features")[1:-1]) == 9
+
+    con.executescript(
+        "INSERT INTO features VALUES(NULL, NULL, NULL); INSERT INTO features VALUES(NULL, 0, 10000000000)"
+    )
+    assert fanout(genomicsqlite.genomic_range_rowids_sql(con, "features")[1:-1]) == 9
+    assert not list(
+        con.execute(genomicsqlite.genomic_range_rowids_sql(con, "features")[1:-1], (None, 123, 456))
+    )
+
+    con.executescript("INSERT INTO features VALUES(42, 1048568, 1048584)")
+    query = genomicsqlite.genomic_range_rowids_sql(con, "features")[1:-1]
+    print("\n" + query)
+    assert " / 4096)" in query  # level 6
+    assert not list(
+        con.execute(
+            genomicsqlite.genomic_range_rowids_sql(con, "features")[1:-1], (42, None, 1048584)
+        )
+    )
+
+    assert fanout(query) == 1
+
+    con.executescript(
+        """
+        INSERT INTO features VALUES(44, 1048568, 1048584);
+        INSERT INTO features VALUES(44, 0, 64000)
+        """
+    )
+    query = genomicsqlite.genomic_range_rowids_sql(con, "features")[1:-1]
+    print("\n" + query)
+    assert " / 65536)" in query  # level 5
+    assert " / 4096)" in query  # level 6
+    assert fanout(query) == 2
+
+    con.executescript(
+        """
+        INSERT INTO features VALUES(43, NULL, 10000000000);
+        INSERT INTO features VALUES(44, 0, NULL)
+        """
+    )
+    assert fanout(genomicsqlite.genomic_range_rowids_sql(con, "features")[1:-1]) == 2
+
+    con.executescript(
+        """
+    INSERT INTO features VALUES(43, 0, 10000000000);
+    INSERT INTO features VALUES(43, 32, 48)
+    """
+    )
+    query = genomicsqlite.genomic_range_rowids_sql(con, "features")[1:-1]
+    print("\n" + query)
+    assert " / 16)" not in query
+    assert fanout(query) == 8
+
+    con.executescript(
+        """
+        INSERT INTO features VALUES(43, 0, 10000000000);
+        INSERT INTO features VALUES(43, 32, 47)
+        """
+    )
+    query = genomicsqlite.genomic_range_rowids_sql(con, "features")[1:-1]
+    assert fanout(query) == 9
+
+
 def test_refseq():
     con = sqlite3.connect(":memory:")