126 lines
5.2 KiB
C#
126 lines
5.2 KiB
C#
// ---------------------------------------------------------------------------
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// <copyright file="IndexFlags.cs" company="Microsoft">
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// Copyright (c) Microsoft Corporation. All rights reserved.
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// </copyright>
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// ---------------------------------------------------------------------------
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// ---------------------------------------------------------------------
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// <summary>
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// </summary>
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// ---------------------------------------------------------------------
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namespace Microsoft.Database.Isam
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{
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using System;
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using Microsoft.Isam.Esent.Interop;
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using Microsoft.Isam.Esent.Interop.Vista;
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/// <summary>
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/// Index flags enumeration
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/// </summary>
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[Flags]
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public enum IndexFlags
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{
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/// <summary>
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/// The index will use the default set of flags.
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/// </summary>
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None = CreateIndexGrbit.None,
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/// <summary>
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/// All keys in the index must be unique or the insertion or update of
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/// the associated record will fail. This uniqueness constraint also
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/// applies to truncated keys.
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/// </summary>
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Unique = CreateIndexGrbit.IndexUnique,
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/// <summary>
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/// The keys in this index represent the primary key for the record.
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/// At this time, the primary index is also the clustered index of the
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/// table. If no primary index is defined for a table then a default
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/// primary index with a sequential key will be used.
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/// </summary>
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Primary = CreateIndexGrbit.IndexPrimary,
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/// <summary>
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/// Each key in the index must have a non-NULL value for every key
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/// column in the index definition or the insertion or update of the
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/// associated record will fail.
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/// </summary>
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DisallowNull = CreateIndexGrbit.IndexDisallowNull,
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/// <summary>
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/// The index will only contain entries for keys with at least one
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/// non-NULL key column.
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/// </summary>
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IgnoreNull = CreateIndexGrbit.IndexIgnoreNull,
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/// <summary>
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/// The index will only contain entries for keys comprised entirely of
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/// non-NULL key columns.
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/// </summary>
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IgnoreAnyNull = CreateIndexGrbit.IndexIgnoreAnyNull,
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/// <summary>
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/// The index will contain entries for keys containing any combination
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/// of NULL and non-NULL key columns. The collation order of NULL key
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/// column values versus non-NULL key column values is determined by the
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/// SortNullsLow and SortNullsHigh IndexFlags. This represents the
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/// default treatment of NULL key column values in an index entry.
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/// </summary>
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AllowNull = CreateIndexGrbit.None,
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/// <summary>
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/// The collation order of the index is set such that NULL key column
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/// values sort closer to the start of the index than non-NULL key
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/// column values. This is the default NULL collation order.
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/// </summary>
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SortNullsLow = CreateIndexGrbit.None,
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/// <summary>
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/// The collation order of the index is set such that NULL key column
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/// values sort closer to the end of the index than non-NULL key column
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/// values.
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/// </summary>
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SortNullsHigh = CreateIndexGrbit.IndexSortNullsHigh,
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/// <summary>
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/// Any key in the index may be larger than the maximum size of the key
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/// supported by that index except that any key beyond the maximum size
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/// will be truncated. This means that there can be no meaningful
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/// relative ordering between keys that are identical after truncation
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/// nor can there be any distinction between entries generated by
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/// different key column values whose keys are identical after
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/// truncation.
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/// <remarks>
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/// This bit is unique to the Isam layer. It is not actually supported
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/// by the underlying database layer. If it is not specified,
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/// <see cref="DisallowTruncation"/> is assumed. This is the opposite default
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/// of the underlying database layer
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/// <para>
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/// <see cref="AllowTruncation"/> and <see cref="DisallowTruncation"/>
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/// are mutually exclusive.
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/// </para>
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/// </remarks>
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/// </summary>
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AllowTruncation = 0x01000000,
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/// <summary>
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/// Each key in the index must be smaller than the maximum size of the
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/// key supported by that index or the insertion or update of the
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/// associated record will fail. Note that at the present time there
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/// is some overhead when converting key column values into a key so
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/// the maximum size of the key will be reached sooner than expected
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/// based on the raw size of the key column values. Truncated keys are
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/// prohibited by default.
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/// </summary>
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/// <remarks>
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/// This is the default behaviour for Isam, but not the default for
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/// the underlying database layer.
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/// <see cref="AllowTruncation"/> and <see cref="DisallowTruncation"/>
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/// are mutually exclusive.
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/// </remarks>
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DisallowTruncation = VistaGrbits.IndexDisallowTruncation,
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}
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}
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