Author: jstephens
Date: 2007-06-23 14:17:22 +0200 (Sat, 23 Jun 2007)
New Revision: 6901
Log:
Added info from WL task HLD/HLS to notes.
Modified:
trunk/ndbapi/NdbRecord-notes-tmp.txt
Modified: trunk/ndbapi/NdbRecord-notes-tmp.txt
===================================================================
--- trunk/ndbapi/NdbRecord-notes-tmp.txt 2007-06-23 12:10:12 UTC (rev 6900)
+++ trunk/ndbapi/NdbRecord-notes-tmp.txt 2007-06-23 12:17:22 UTC (rev 6901)
Changed blocks: 1, Lines Added: 296, Lines Deleted: 0; 10873 bytes
@@ -1,3 +1,299 @@
+***** WL#2223: *****
+
+Pushed into 5.1-telco tree 2007-05-31 -> telco-6.2.3 (not yet released)
+
+HLD:
+
+Introduce NdbRecord
+NdbRecord is linear memory per operation
+NdbRecord can be mapped (almost) directly to mysql record
+
+Lots of code can be removed and
+Lots of optimizations can be added if using records.
+
+It's further more quite simple to make this backward compatible
+
+---
+
+a NdbRecord-object provides mapping to a full or a partial record stored in ndb
+a NdbRecord can also be used together with bitmap for access of partial NdbRecord
+
+a NdbRecord is prepared by API program
+a NdbRecord is validated and finalized by ndbapi
+a NdbRecord-object can be used simultanious
+ in several operations
+ in several transactions
+ in several threads
+ (i.e the actual NdbRecord object should not contain any data references)
+
+Usage of NdbRecord can be phased (as devliverables or internally as)
+* uk read
+* pk read
+* table scan
+* index scan
+* pk dml
+* uk dml
+* index bounds
+
+* wl1496 is concidered depandant on this wl, as it will be soo much simpler
+ to impl. once this is done
+
+---
+
+Logically readTuple(NdbRecord) <=> readTuples() getValue on each col in record
+ insertTuple(NdbRecord) <=> inserTuple() setValue on each col in record
+ etc...
+
+HLS (probably not so useful for docs but I'm including it here anyroad):
+
+NdbRecord *record= dict->createRecord(table, record_specification,
+number_of_coulmns, sizeof(record_specification[0]);
+
+NdbRecord *key_record= dict->createRecord(table, record_specification,
+number_of_key_coulmns, sizeof(record_specification[0]);
+
+char* buf0 = malloc(sizeof(TUPLE));
+char* buf1 = malloc(sizeof(TUPLE));
+char* buf2 = malloc(sizeof(TUPLE));
+
+// set key in buf0
+// set key in buf1
+
+ // Read all columns in record into buf2
+op0 = pTrans->readTuple(key_record, buf0, record, buf2,LM_Read, 0);
+
+ // Read all columns in record & columnmask
+op0 = pTrans->readTuple(key_record, buf0, record, buf2,LM_Read, columnmask);
+
+API:
+
+struct RecordSpecification {
+ /*
+ Column described by this entry (the column maximum size defines field
+ size in row).
+ Note that even when creating an NdbRecord for an index, the column
+ pointers must be to columns obtained from the underlying table, not
+ from the index itself.
+ */
+ const Column *column;
+ /* Offset of data from start of a row. */
+ Uint32 offset;
+ /* Offset from start of row of byte containing NULL bit. */
+ Uint32 nullbit_byte_offset;
+ /* NULL bit, 0-7. */
+ Uint32 nullbit_bit_in_byte;
+};
+
+class NdbDictionary {
+ ...
+ /*
+ Create an NdbRecord for use in table operations.
+ */
+ NdbRecord *createRecord(const Table *table,
+ const RecordSpecification *recSpec,
+ Uint32 length,
+ Uint32 elemSize);
+
+ /*
+ Create an NdbRecord for use in index operations.
+ */
+ NdbRecord *createRecord(const Index *index,
+ const Table *table,
+ const RecordSpecification *recSpec,
+ Uint32 length,
+ Uint32 elemSize);
+ void releaseRecord(NdbRecord *rec);
+};
+
+class NdbTransaction {
+ ...
+ /* Primary key NdbRecord operations. */
+ NdbOperation *readTuple(const NdbRecord *key_rec, const char *key_row,
+ const NdbRecord *result_rec, char *result_row,
+ NdbOperation::LockMode lock_mode= NdbOperation::LM_Read,
+ const unsigned char *result_mask= 0);
+ NdbOperation *insertTuple(const NdbRecord *rec, const char *row,
+ const unsigned char *mask= 0);
+ NdbOperation *updateTuple(const NdbRecord *key_rec, const char *key_row,
+ const NdbRecord *attr_rec, const char *attr_row,
+ const unsigned char *mask= 0);
+ NdbOperation *writeTuple(const NdbRecord *key_rec, const char *key_row,
+ const NdbRecord *attr_rec, const char *attr_row,
+ const unsigned char *mask);
+ NdbOperation *deleteTuple(const NdbRecord *key_rec, const char *key_row);
+
+ /*
+ Scan a table, using NdbRecord to read out column data.
+
+ The result_record pointer must remain valid until after the call to
+ execute().
+
+ The result_mask pointer is optional, if present only columns for which
+ the corresponding bit in result_mask is set will be retrieved in the
+ scan. The result_mask is copied internally, so in contrast to
+ result_record need not be valid at execute().
+
+ The parallel argument is the desired parallelism, or 0 for maximum
+ parallelism (receiving rows from all fragments in parallel).
+ */
+ NdbScanOperation *
+ scanTable(const NdbRecord *result_record,
+ NdbOperation::LockMode lock_mode= NdbOperation::LM_Read,
+ const unsigned char *result_mask= 0,
+ Uint32 scan_flags= 0,
+ Uint32 parallel= 0,
+ Uint32 batch= 0);
+
+ /*
+ Do an index range scan (optionally ordered) of a table.
+
+ The key_record describes the index to be scanned. It must be a
+ primary key record for the index, ie. it must specify exactly the
+ key columns of the index.
+
+ The result_record describes the rows to be returned from the scan. For an
+ ordered index scan, result_record must be a key record for the index to
+ be scanned, that is it must include at least all of the column in the
+ index.
+
+ Both the key_record and the result_record must be created from the Index
+ to be scanned, not from the underlying table.
+
+ The call uses a callback function as a flexible way of specifying multiple
+ range bounds. The callback will be called once for each bound to define
+ lower and upper key value etc.
+
+ The callback received a private callback_data void *, and the index of the
+ bound (0 .. num_key_bounds). However, it is guaranteed that it will be
+ called in ordered sequence, so it is permissible to ignore the passed
+ bound_index and just return the values for the next bound (for example
+ if data is kept in a linked list).
+
+ The callback can return 0 to denote success, and -1 to denote error (the
+ latter causing the creation of the NdbIndexScanOperation to fail).
+
+ This multi-range method is only for use in mysqld code.
+ */
+private:
+ NdbIndexScanOperation *
+ scanIndex(const NdbRecord *key_record,
+ int (*get_bound_callback)(void *callback_data,
+ Uint32 bound_index,
+ NdbIndexScanOperation::IndexBound & bound),
+ void *callback_data,
+ Uint32 num_key_bounds,
+ const NdbRecord *result_record,
+ NdbOperation::LockMode lock_mode= NdbOperation::LM_Read,
+ const unsigned char *result_mask= 0,
+ Uint32 scan_flags= 0,
+ Uint32 parallel= 0,
+ Uint32 batch= 0);
+
+public:
+
+ /* A convenience wrapper for simpler specification of a single bound. */
+ NdbIndexScanOperation *
+ scanIndex(const NdbRecord *key_record,
+ const char *low_key,
+ Uint32 low_key_count,
+ bool low_inclusive,
+ const char * high_key,
+ Uint32 high_key_count,
+ bool high_inclusive,
+ const NdbRecord *result_record,
+ NdbOperation::LockMode lock_mode= NdbOperation::LM_Read,
+ const unsigned char *result_mask= 0,
+ Uint32 scan_flags= 0,
+ Uint32 parallel= 0,
+ Uint32 batch= 0);
+
+};
+
+class NdbScanOperation {
+ ...
+ /*
+ NdbRecord version of nextResult.
+ This sets a pointer to the next row in out_row (if returning 0). This
+ pointer is valid (only) until the next call to nextResult() with
+ fetchAllowed==true.
+ The NdbRecord object defining the row format was specified in the
+ NdbTransaction::scanTable (or scanIndex) call.
+ */
+ int nextResult(const char * & out_row,
+ bool fetchAllowed = true, bool forceSend = false);
+
+ /*
+ NdbRecord versions of scan lock take-over operations.
+
+ Note that calling NdbRecord scan lock take-over on an NdbRecAttr-style
+ scan is not valid, nor is calling NdbRecAttr-style scan lock take-over
+ on an NdbRecord-style scan.
+ */
+
+ /*
+ Take over the lock without changing the row.
+ Optionally also read from the row (call with default value NULL for row
+ to not read any attributes.).
+ The NdbRecord * is required even when not reading any attributes.
+ */
+ NdbOperation *lockCurrentTuple(NdbTransaction *takeOverTrans,
+ const NdbRecord *record,
+ char *row= 0,
+ const unsigned char *mask= 0);
+
+ /*
+ Update the current tuple, NdbRecord version.
+ Values to update with are contained in the passed-in row.
+ */
+ NdbOperation *updateCurrentTuple(NdbTransaction *takeOverTrans,
+ const NdbRecord *record,
+ const char *row,
+ const unsigned char *mask= 0);
+
+ /* Delete the current tuple. */
+ NdbOperation *deleteCurrentTuple(NdbTransaction *takeOverTrans,
+ const NdbRecord *record);
+
+};
+
+class NdbIndexScanOperation {
+ ...
+ /* Structure used to describe index scan bounds, for NdbRecord scans. */
+ struct IndexBound {
+ /* Row containing lower bound, or NULL for scan from the start. */
+ const char *low_key;
+ /* Number of columns in lower bound, for bounding by partial prefix. */
+ Uint32 low_key_count;
+ /* True for less-than-or-equal, false for strictly less-than. */
+ bool low_inclusive;
+ /* Row containing upper bound, or NULL for scan to the end. */
+ const char * high_key;
+ /* Number of columns in upper bound, for bounding by partial prefix. */
+ Uint32 high_key_count;
+ /* True for greater-than-or-equal, false for strictly greater-than. */
+ bool high_inclusive;
+ /*
+ Value to identify this bound, may be read with get_range_no().
+ Must be < 8192 (set to zero if not using range_no).
+ Note that for ordered scans, the range_no must be strictly increasing
+ for each range, or the result set will not be sorted correctly.
+ */
+ Uint32 range_no;
+ };
+};
+
+
+
+***** WL#3733: NdbRecord optimisation for mysqld *****...
+
+
+Not muc to document other than that the optimisations went into
+5.1-telco tree 2007-05-31 -> telco-6.2.3 release.
+
+Just need to note improved performance.
+
+Grepping for references to NdbRecord in NDBAPI include files...
+
jon@biollante:~/bk/mysql-5.1-telco/storage/ndb/include/ndbapi> grep -R -n 'NdbRecord' ./
./NdbScanOperation.hpp:180: NdbRecord version of nextResult.
./NdbScanOperation.hpp:184: The NdbRecord object defining the row format was specified in the
| Thread |
|---|
| • svn commit - mysqldoc@docsrva: r6901 - trunk/ndbapi | jon | 23 Jun |
