dremio SchemaMutability 属于一个枚举，定义了schema 的可变性能力()
参考定义
public enum SchemaMutability {
@Tag(1)
ALL(true, true, true, true),
@Tag(2)
NONE(false, false, false, false),
@Tag(3)
SYSTEM_TABLE(false, true, false, false),
@Tag(4)
SYSTEM_TABLE_AND_VIEW(false, true, false, true),
@Tag(5)
SYSTEM_VIEW(false, false, false, true),
@Tag(6)
USER_TABLE(true, true, false, false),
@Tag(7)
USER_VIEW(false, false, true, true),
@Tag(8)
USER_TABLE_AND_VIEW(true, true, true, true);
final boolean anyoneMutateTable;
final boolean systemMutateTable;
final boolean anyoneMutateView;
final boolean systemMutateView;
private SchemaMutability(
boolean anyoneMutateTable,
boolean systemMutateTable,
boolean anyoneMutateView,
boolean systemMutateView) {
this.anyoneMutateTable = anyoneMutateTable;
this.systemMutateTable = systemMutateTable;
this.anyoneMutateView = anyoneMutateView;
this.systemMutateView = systemMutateView;
}
public boolean hasMutationCapability(MutationType type, boolean isSystemUser) {
if (isSystemUser) {
switch (type) {
case VIEW:
return systemMutateView;
case TABLE:
return systemMutateTable;
default:
throw new IllegalStateException();
}
}
switch (type) {
case VIEW:
return anyoneMutateView;
case TABLE:
return anyoneMutateTable;
default:
throw new IllegalStateException();
}
}
public static enum MutationType {
VIEW,
TABLE
}
}
使用
dremio 在一些系统存储插件中就进行了明确的能力定义
- 比如home 的
createSafe(
catalogService,
ns,
HomeFileConf.create(
HomeFileSystemStoragePlugin.HOME_PLUGIN_NAME,
uploadsPathConfig.getUri(),
config.getThisNode(),
SchemaMutability.USER_TABLE,
CatalogService.NEVER_REFRESH_POLICY,
enableAsyncForUploads,
scratchPathConfig.getDataCredentials()),
deferred);
- FileSystemConf 抽象接口定义
相关实现上都会包含能力的定义
public abstract class FileSystemConf<C extends FileSystemConf<C, P>, P extends FileSystemPlugin<C>>
extends ConnectionConf<C, P> implements AsyncStreamConf, MutablePluginConf {
public abstract Path getPath();
public abstract boolean isImpersonationEnabled();
public abstract List<Property> getProperties();
public abstract String getConnection();
public abstract boolean isPartitionInferenceEnabled();
public abstract SchemaMutability getSchemaMutability();
s3 文件系统扩展的处理
@Override
public SchemaMutability getSchemaMutability() {
return SchemaMutability.USER_TABLE;
}
- 处理
核心是内部的判定文件系统时候支持特定的操作，比如view，table，比如dropview 的处理
public void dropView(
NamespaceKey tableSchemaPath, ViewOptions viewOptions, SchemaConfig schemaConfig)
throws IOException {
if (!Boolean.getBoolean(DremioConfig.LEGACY_STORE_VIEWS_ENABLED)) {
throw UserException.parseError()
.message("Unable to drop view. Filesystem views are not supported.")
.build(logger);
} else if (!getMutability()
.hasMutationCapability(MutationType.VIEW, schemaConfig.isSystemUser())) {
throw UserException.parseError()
.message("Unable to drop view. Schema [%s] is immutable for this user.", this.name)
.build(logger);
}
createFS(schemaConfig.getUserName())
.delete(getViewPath(tableSchemaPath.getPathComponents()), false);
}
完整的如下图
说明
目前jdbc类的存储插件（arp）的没有此配置
参考资料
dac/backend/src/main/java/com/dremio/dac/daemon/SystemStoragePluginInitializer.java
common/legacy/src/main/java/com/dremio/exec/store/dfs/SchemaMutability.java
sabot/kernel/src/main/java/com/dremio/exec/store/dfs/FileSystemConf.java