try

Author: LiamHamsters

src/EFCore.Ydb/src/Storage/Internal/YdbTypeMappingSource.cs

@@ -111,13 +111,13 @@ RelationalTypeMappingSourceDependencies relationalDependencies
         { typeof(TimeSpan), Interval }
     };
 
-    private static readonly ConcurrentDictionary<RelationalTypeMappingInfo, RelationalTypeMapping> DecimalCache = new();
+    private readonly ConcurrentDictionary<RelationalTypeMappingInfo, RelationalTypeMapping> _decimalCache = new();
 
     protected override RelationalTypeMapping? FindMapping(in RelationalTypeMappingInfo mappingInfo)
     {
         if (mappingInfo.ClrType == typeof(decimal))
         {
-            return DecimalCache.GetOrAdd(mappingInfo, static mi => Decimal.Clone(mi));
+            return _decimalCache.GetOrAdd(mappingInfo, static mi => Decimal.Clone(mi));
         }
 
         return base.FindMapping(mappingInfo) ?? FindBaseMapping(mappingInfo)?.Clone(mappingInfo);

src/EFCore.Ydb/test/EntityFrameworkCore.Ydb.FunctionalTests/Query/DecimalParameterizedYdbTheoryTest.cs

@@ -9,6 +9,9 @@ namespace EntityFrameworkCore.Ydb.FunctionalTests.Query;
 public class DecimalParameterizedYdbTheoryTest(DecimalParameterQueryYdbFixture fixture)
     : IClassFixture<DecimalParameterQueryYdbFixture>
 {
+    static DecimalParameterizedYdbTheoryTest()
+        => AppContext.SetSwitch("EntityFrameworkCore.Ydb.EnableParametrizedDecimal", true);
+    
     private DbContextOptions<ParametricDecimalContext> BuildOptions()
     {
         using var baseCtx = fixture.CreateContext();
@@ -91,6 +94,7 @@ public async Task Decimal_roundtrips_or_rounds_like_ado(int p, int s, decimal va
     [MemberData(nameof(OverflowCases))]
     public async Task Decimal_overflow_bubbles_up(int p, int s, decimal value)
     {
+        AppContext.SetSwitch("EntityFrameworkCore.Ydb.EnableParametrizedDecimal", true);
         await using var ctx = NewCtx(p, s);
         await ctx.Database.EnsureCreatedAsync();
 

src/EFCore.Ydb/test/EntityFrameworkCore.Ydb.FunctionalTests/Query/ParametricDecimalContext.cs

@@ -30,10 +30,9 @@ internal sealed class CacheKeyFactory : IModelCacheKeyFactory
         public object Create(DbContext context, bool designTime)
         {
             var ctx = (ParametricDecimalContext)context;
+            var flag = AppContext.TryGetSwitch("EntityFrameworkCore.Ydb.EnableParametrizedDecimal", out var on) && on;
 
-            var options = context.GetService<IDbContextOptions>();
-
-            return (context.GetType(), designTime, ctx._p, ctx._s, options.Extensions);
+            return (context.GetType(), designTime, ctx._p, ctx._s, flag);
         }
     }
 }