Loading a lot of rows containing merged cells slows down

[fukasawah]

I gave it 10,000 rows of data, it became very slow.

But, Setting search_merged_cell: false will work.
It looks like it slows down in proportion to the number of merged cells.

I think the following code is being processed on a per Cell basis and is slow.

embulk-parser-poi_excel/src/main/java/org/embulk/parser/poi_excel/visitor/PoiExcelCellValueVisitor.java

Lines 86 to 89 in 0db4cab

	Sheet sheet = cell.getSheet();
	int size = sheet.getNumMergedRegions();
	for (int i = 0; i < size; i++) {
	CellRangeAddress range = visitorValue.getSheet().getMergedRegion(i);

Test data and config.yml here. reports.zip

[hishidama]

In version 0.1.10, changed search_merged_cell false,true to none,linear_search,tree_search. (default: tree_search)
tree_search is faster than linear_search, but uses a lot of memory.