1. Do not retry publishing on be When there are too many missing versions, just
add to async publish task.
2. To reduce memory consumption, clean up the tasks when there are too many
async publish tasks.
Refactor write path code by abstract base class. Whether to use `StorageEngine` or `CloudStorageEngine` will be determined during compilation instead of runtime `config::cloud_mode` to avoid unexpected null pointer or undefined behavior issues caused by merging code.
Class that depend on `StorageEngine` but are shared by the cloud mode need to have an abstract base class. Common code should be extracted into the base class, while the code that depends on `StorageEngine` should be implemented in a `StorageEngine` mix-in class of the base class.
* Optimize fetch delete predicates
* Fix incorrect query result when compaction eliminate delete predicates between `NewOlapScanNode::_init_scanners` and `NewOlapScanner::init`
* Fix be ut
Current initialization dependency:
Daemon ───┬──► StorageEngine ──► ExecEnv ──► Disk/Mem/CpuInfo
│
│
BackendService ─┘
However, original code incorrectly initialize Daemon before StorageEngine.
This PR also stop and join threads of daemon services in their dtor, to ensure Daemon services release resources in reverse order of initialization via RAII.
New structure for delete sub predicate.
Delete sub predicate uses a string type condition_str to stored temporarily now and fields will be extracted from it using std::regex, which may introduces stack overflow when matching a extremely large string(bug of libc).
Now we attempt to use a new PB structure to hold the delete sub predicate, to avoid that problem.
message DeleteSubPredicatePB {
optional int32 column_unique_id = 1;
optional string column_name = 2;
optional string op = 3;
optional string cond_value = 4;
}
Currently, 2 versions of sub predicate will both be filled. For query, we use the v2, and during compaction we still use v1. The old rowset meta with delete predicates which had sub predicate v1 will be attempted to convert to v2 when read from PB. Moreover, efforts will be made to rewrite these meta with the new delete sub predicate.
Make preparation to use column unique id to specify a column globally.
Using the column unique id rather than the column name to identify a column is vital for flexible schema change. The rewritten delete predicate will attach column unique id.
Previously, delete statement with conditions on value columns are only supported on duplicate tables. After we introduce delete sign mechanism to do batch delete, a delete statement with conditions on value columns on unique tables will be transformed into the corresponding insert into ..., __DELETE_SIGN__ select ... statement. However, for unique table with merge-on-write enabled, the overhead of inserting these data can be eliminated. So this PR add the ability to allow delete predicate on value columns for merge-on-write unique tables.
