Disable MultipleParameters for now

See #3269

Author: roji

src/EFCore.PG/Infrastructure/Internal/NpgsqlOptionsExtension.cs

@@ -11,11 +11,25 @@ namespace Npgsql.EntityFrameworkCore.PostgreSQL.Infrastructure.Internal;
 public class NpgsqlOptionsExtension : RelationalOptionsExtension
 {
     private DbContextOptionsExtensionInfo? _info;
+    private ParameterizedCollectionMode? _parameterizedCollectionMode;
+
     private readonly List<UserRangeDefinition> _userRangeDefinitions;
     private readonly List<EnumDefinition> _enumDefinitions;
-
     private Version? _postgresVersion;
 
+    // We override ParameterizedCollectionMode to set Parameter as the default instead of MultipleParameters,
+    // which is the EF relational default. In PostgreSQL using native array parameters is better, and the
+    // query plan problem can be mitigated by telling PostgreSQL to use a custom plan (see #3269).
+
+    /// <summary>
+    ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
+    ///     the same compatibility standards as public APIs. It may be changed or removed without notice in
+    ///     any release. You should only use it directly in your code with extreme caution and knowing that
+    ///     doing so can result in application failures when updating to a new Entity Framework Core release.
+    /// </summary>
+    public override ParameterizedCollectionMode ParameterizedCollectionMode
+        => _parameterizedCollectionMode ?? ParameterizedCollectionMode.Parameter;
+
     /// <summary>
     ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
     ///     the same compatibility standards as public APIs. It may be changed or removed without notice in
@@ -132,6 +146,17 @@ public NpgsqlOptionsExtension(NpgsqlOptionsExtension copyFrom)
     public override int? MinBatchSize
         => base.MinBatchSize ?? 2;
 
+    // We need to override WithUseParameterizedCollectionMode since we override ParameterizedCollectionMode above
+    /// <inheritdoc />
+    public override RelationalOptionsExtension WithUseParameterizedCollectionMode(ParameterizedCollectionMode parameterizedCollectionMode)
+    {
+        var clone = (NpgsqlOptionsExtension)Clone();
+
+        clone._parameterizedCollectionMode = parameterizedCollectionMode;
+
+        return clone;
+    }
+
     /// <summary>
     ///     Creates a new instance with all options the same as for this instance, but with the given option changed.
     ///     It is unusual to call this method directly. Instead use <see cref="DbContextOptionsBuilder" />.