Fix select by part of sharding key equal

Before this patch it wasn't checked that all fields of sharding key
are specified if scan index is a sharding index
detect if fully sharding key is specified
So, for select w/ {'=', 'primary', {0, nil}} condition was performed on
the only one storage and it returned only one tuple

Author: dokshina

CHANGELOG.md

@@ -10,6 +10,9 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 ### Fixed
 
 * Fixed typo in error for case when failed to get `bucket_id`
+* Fixed select by part of sharding key equal. Before this patch
+  selecting by equality of partially specified multipart primary index
+  value was misinterpreted as a selecting by fully specified key value.
 
 ## [0.3.0] - 2020-10-26
 

crud/select/plan.lua

@@ -53,14 +53,18 @@ local function validate_conditions(conditions, space_indexes, space_format)
     return true
 end
 
-local function extract_sharding_key_from_scan_key(scan_key, scan_index, sharding_index)
+local function extract_sharding_key_from_scan_value(scan_value, scan_index, sharding_index)
+    if #scan_value < #sharding_index.parts then
+        return nil
+    end
+
     if scan_index.id == sharding_index.id then
-        return scan_key
+        return scan_value
     end
 
-    local scan_key_fields_values = {}
-    for i, scan_key_part in ipairs(scan_index.parts) do
-        scan_key_fields_values[scan_key_part.fieldno] = scan_key[i]
+    local scan_value_fields_values = {}
+    for i, scan_index_part in ipairs(scan_index.parts) do
+        scan_value_fields_values[scan_index_part.fieldno] = scan_value[i]
     end
 
     -- check that sharding key is included in the scan index fields
@@ -69,11 +73,11 @@ local function extract_sharding_key_from_scan_key(scan_key, scan_index, sharding
         local fieldno = sharding_key_part.fieldno
 
         -- sharding key isn't included in scan key
-        if scan_key_fields_values[fieldno] == nil then
+        if scan_value_fields_values[fieldno] == nil then
             return nil
         end
 
-        local field_value = scan_key_fields_values[fieldno]
+        local field_value = scan_value_fields_values[fieldno]
 
         -- sharding key contains nil values
         if field_value == nil then
@@ -165,7 +169,7 @@ function select_plan.new(space, conditions, opts)
     -- get sharding key value
     local sharding_key
     if scan_value ~= nil and (scan_iter == box.index.EQ or scan_iter == box.index.REQ) then
-        sharding_key = extract_sharding_key_from_scan_key(scan_value, scan_index, sharding_index)
+        sharding_key = extract_sharding_key_from_scan_value(scan_value, scan_index, sharding_index)
     end
 
     if sharding_key ~= nil then

test/entrypoint/srv_select.lua

@@ -51,12 +51,34 @@ package.preload['customers-storage'] = function()
             })
             customers_space:create_index('full_name', {
                 parts = {
-                    { field = 'name', collation = 'unicode_ci' },
-                    { field = 'last_name', collation = 'unicode_ci' },
+                    {field = 'name', collation = 'unicode_ci'},
+                    {field = 'last_name', collation = 'unicode_ci'} ,
                 },
                 unique = false,
                 if_not_exists = true,
             })
+
+            local coord_space = box.schema.space.create('coord', {
+                format = {
+                      {name = 'x', type = 'unsigned'},
+                      {name = 'y', type = 'unsigned'},
+                      {name = 'bucket_id', type = 'unsigned'},
+                },
+                if_not_exists = true,
+                engine = engine,
+            })
+            -- primary index
+            coord_space:create_index('primary', {
+                parts = {
+                    {field = 'x'},
+                    {field = 'y'},
+                },
+                if_not_exists = true,
+            })
+            coord_space:create_index('bucket_id', {
+                parts = { {field = 'bucket_id'} },
+                if_not_exists = true,
+            })
         end,
         dependencies = {'cartridge.roles.crud-storage'},
     }

test/integration/select_test.lua

@@ -791,3 +791,25 @@ add('test_select_with_collations', function(g)
     local objects = crud.unflatten_rows(result.rows, result.metadata)
     t.assert_equals(objects, helpers.get_objects_by_idxs(customers, {2, 4}))
 end)
+
+add('test_multipart_primary_index', function(g)
+    local coords = helpers.insert_objects(g, 'coord', {
+        { x = 0, y = 0 }, -- 1
+        { x = 0, y = 1 }, -- 2
+        { x = 0, y = 2 }, -- 3
+        { x = 1, y = 3 }, -- 4
+        { x = 1, y = 4 }, -- 5
+    })
+
+    local conditions = {{'=', 'primary', 0}}
+    local result, err = g.cluster.main_server.net_box:call('crud.select', {'coord', conditions})
+    t.assert_equals(err, nil)
+    local objects = crud.unflatten_rows(result.rows, result.metadata)
+    t.assert_equals(objects, helpers.get_objects_by_idxs(coords, {1, 2, 3}))
+
+    local conditions = {{'=', 'primary', {0, 2}}}
+    local result, err = g.cluster.main_server.net_box:call('crud.select', {'coord', conditions})
+    t.assert_equals(err, nil)
+    local objects = crud.unflatten_rows(result.rows, result.metadata)
+    t.assert_equals(objects, helpers.get_objects_by_idxs(coords, {3}))
+end)

test/unit/select_filters_test.lua

@@ -37,8 +37,8 @@ g.before_all = function()
     })
     customers_space:create_index('full_name', { -- id: 2
         parts = {
-            { field = 'name', collation = 'unicode_ci' },
-            { field = 'last_name', is_nullable = true },
+            {field = 'name', collation = 'unicode_ci'},
+            {field = 'last_name', is_nullable = true},
         },
         unique = false,
         if_not_exists = true,

test/unit/select_plan_bad_indexes_test.lua

@@ -54,8 +54,8 @@ g.before_all = function()
     customers_space:create_index('full_name_hash', {
         type = 'HASH',
         parts = {
-            { field = 'name', collation = 'unicode_ci' },
-            { field = 'last_name'},
+            {field = 'name', collation = 'unicode_ci'},
+            {field = 'last_name'},
         },
         if_not_exists = true,
     })

test/unit/select_plan_test.lua

@@ -33,8 +33,8 @@ g.before_all = function()
     })
     customers_space:create_index('full_name', { -- id: 2
         parts = {
-            { field = 'name', collation = 'unicode_ci' },
-            { field = 'last_name', is_nullable = true },
+            {field = 'name', collation = 'unicode_ci'},
+            {field = 'last_name', is_nullable = true},
         },
         unique = false,
         if_not_exists = true,
@@ -44,6 +44,25 @@ g.before_all = function()
         unique = false,
         if_not_exists = true,
     })
+
+    -- is used for multipart primary index tests
+    local coord_space = box.schema.space.create('coord', {
+        format = {
+              {name = 'x', type = 'unsigned'},
+              {name = 'y', type = 'unsigned'},
+              {name = 'bucket_id', type = 'unsigned'},
+        },
+        if_not_exists = true,
+    })
+     -- primary index
+    coord_space:create_index('primary', {
+        parts = { {field = 'x'}, {field = 'y'} },
+        if_not_exists = true,
+    })
+    coord_space:create_index('bucket_id', {
+        parts = { {field = 'bucket_id'} },
+        if_not_exists = true,
+    })
 end
 
 g.after_all(function()
@@ -187,6 +206,28 @@ g.test_is_scan_by_full_sharding_key_eq = function()
 
     t.assert_equals(plan.total_tuples_count, nil)
     t.assert_equals(plan.sharding_key, nil)
+
+    -- multipart primary index
+
+    -- specified only first part
+    local plan, err = select_plan.new(box.space.coord, {
+        cond_funcs.eq('primary', 0),
+    })
+
+    t.assert_equals(err, nil)
+
+    t.assert_equals(plan.total_tuples_count, nil)
+    t.assert_equals(plan.sharding_key, nil)
+
+    -- specified both parts
+    local plan, err = select_plan.new(box.space.coord, {
+        cond_funcs.eq('primary', {1, 0}),
+    })
+
+    t.assert_equals(err, nil)
+
+    t.assert_equals(plan.total_tuples_count, 1)
+    t.assert_equals(plan.sharding_key, {1, 0})
 end
 
 g.test_first = function()