nopSolutions/nopCommerce · error · DataException

This database provider does not support database shrinking.

Error message

This database provider does not support database shrinking.  Instead, use Re-index operation to optimize database space. Optimization is only available when the 'innodb_file_per_table' setting is enabled

What it means

MySqlDataProvider.ShrinkDatabaseAsync throws DataException because InnoDB does not shrink via a single SQL command. The message directs the operator to ReIndexTablesAsync (which runs OPTIMIZE TABLE) and notes OPTIMIZE only reclaims file space when innodb_file_per_table is enabled. PostgreSQL and SQL Server providers do implement shrink (VACUUM FULL / DBCC SHRINKDATABASE).

Source

Thrown at src/Libraries/Nop.Data/DataProviders/MySqlDataProvider.cs:264

    /// Re-index database tables
    /// </summary>
    /// <returns>A task that represents the asynchronous operation</returns>
    public virtual async Task ReIndexTablesAsync()
    {
        using var currentConnection = CreateDataConnection();
        var tables = currentConnection.Query<string>($"SHOW TABLES FROM `{GetConnectionStringBuilder().Database}`").ToList();

        if (tables.Count > 0)
            await currentConnection.ExecuteAsync($"OPTIMIZE TABLE `{string.Join("`, `", tables)}`");
    }

    /// <summary>
    /// Shrinks database
    /// </summary>
    /// <returns>A task that represents the asynchronous operation</returns>
    public virtual Task ShrinkDatabaseAsync()
    {
        throw new DataException("This database provider does not support database shrinking.  Instead, use Re-index operation to optimize database space. Optimization is only available when the 'innodb_file_per_table' setting is enabled");
    }

    /// <summary>
    /// Gets the database size in Kb
    /// </summary>
    /// <returns>
    /// A task that represents the asynchronous operation
    /// The task result contains the database size
    /// </returns>
    public virtual async Task<long> GetDatabaseSizeAsync()
    {
        using var currentConnection = CreateDataConnection();
        var result = await currentConnection.QueryToListAsync<long>($"SELECT ROUND(SUM(data_length + index_length) / 1024, 1) FROM information_schema.tables where table_schema='{GetConnectionStringBuilder().Database}' GROUP BY table_schema");

        return result.FirstOrDefault();
    }

    /// <summary>

View on GitHub (pinned to 64bdf2ff08)

Solutions

Call ReIndexTablesAsync() instead for MySQL — it runs OPTIMIZE TABLE to compact tables.
Ensure the MySQL server has innodb_file_per_table=ON, otherwise OPTIMIZE TABLE will not return disk to the OS.
Guard shrink behind a DataProviderType check and only run it for SQL Server / PostgreSQL.

Example fix

// before
await dataProvider.ShrinkDatabaseAsync();

// after
if (DataSettings.DataProvider is DataProviderType.SqlServer or DataProviderType.PostgreSQL)
    await dataProvider.ShrinkDatabaseAsync();
else
    await dataProvider.ReIndexTablesAsync(); // MySQL OPTIMIZE TABLE

Defensive patterns

Strategy: fallback

Validate before calling

if (DataSettings.DataProvider == DataProviderType.MySql)
    await dataProvider.ReIndexTablesAsync(); // OPTIMIZE TABLE
else
    await dataProvider.ShrinkDatabaseAsync();

Type guard

static bool SupportsShrink(DataProviderType t) => t is DataProviderType.SqlServer or DataProviderType.PostgreSQL;

Try / catch

try { await dataProvider.ShrinkDatabaseAsync(); }
catch (DataException) when (DataSettings.DataProvider == DataProviderType.MySql)
{ await dataProvider.ReIndexTablesAsync(); } // OPTIMIZE TABLE as the supported alternative

Prevention

On MySQL use ReIndexTablesAsync (OPTIMIZE TABLE) instead of shrink.
Ensure innodb_file_per_table=ON so OPTIMIZE reclaims OS disk.
Gate shrink calls on provider type.

When it happens

Trigger: A maintenance routine or admin button calls dataProvider.ShrinkDatabaseAsync() on a MySQL store. The MySQL provider has no shrink implementation, so it always throws this DataException.

Common situations: Operator tries to reclaim disk after large deletes on MySQL; a scheduled job written generically calls shrink on every provider; migrating from SQL Server where shrink worked.

Related errors

AI-assisted analysis of nopSolutions/nopCommerce@64bdf2ff08 (2026-08-13). Data as JSON: /api/errors/bd93773ad8c4946e. Report an issue: GitHub.