44 lines
1.6 KiB
Go
44 lines
1.6 KiB
Go
// Copyright 2021 PingCAP, Inc.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package variable
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// Removed sysvars is a way of removing sysvars, while allowing limited
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// Parse-but-ignore support in SET context, and a more specific error in
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// SELECT @@varname context.
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//
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// This helps ensure some compatibility for applications while being
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// careful not to return dummy data.
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var removedSysVars = map[string]string{
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TiDBEnableAlterPlacement: "alter placement is now always enabled",
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TiDBEnableGlobalTemporaryTable: "temporary table support is now always enabled",
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TiDBSlowLogMasking: "use tidb_redact_log instead",
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PlacementChecks: "placement_checks is removed and use tidb_placement_mode instead",
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}
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// IsRemovedSysVar returns true if the sysvar has been removed
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func IsRemovedSysVar(varName string) bool {
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_, ok := removedSysVars[varName]
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return ok
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}
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// CheckSysVarIsRemoved returns an error if the sysvar has been removed
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func CheckSysVarIsRemoved(varName string) error {
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if reason, ok := removedSysVars[varName]; ok {
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return ErrVariableNoLongerSupported.GenWithStackByArgs(varName, reason)
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}
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return nil
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}
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