postgresql 索引损坏

ERROR,XX000,"right sibling's left-link doesn't match: block 53485 links to 31332  instead of expected 31324 in index ""xxx""",

create index concurrently on xx(xx);
drop index concurrently corr_idex;

/*
     * Check that the parent-page index items we're about to delete/overwrite
     * in subtree parent page contain what we expect.  This can fail if the
     * index has become corrupt for some reason.  We want to throw any error
     * before entering the critical section --- otherwise it'd be a PANIC.
     */
    page = BufferGetPage(subtreeparent);
    opaque = (BTPageOpaque) PageGetSpecialPointer(page);


#ifdef USE_ASSERT_CHECKING


    /*
     * This is just an assertion because _bt_lock_subtree_parent should have
     * guaranteed tuple has the expected contents
     */
    itemid = PageGetItemId(page, poffset);
    itup = (IndexTuple) PageGetItem(page, itemid);
    Assert(BTreeTupleGetDownLink(itup) == topparent);
#endif


    nextoffset = OffsetNumberNext(poffset);
    itemid = PageGetItemId(page, nextoffset);
    itup = (IndexTuple) PageGetItem(page, itemid);
    if (BTreeTupleGetDownLink(itup) != topparentrightsib)
        ereport(ERROR,
                (errcode(ERRCODE_INDEX_CORRUPTED),
                 errmsg_internal("right sibling %u of block %u is not next child %u of block %u in index \"%s\"",
                                 topparentrightsib, topparent,
                                 BTreeTupleGetDownLink(itup),
                                 BufferGetBlockNumber(subtreeparent),
                                 RelationGetRelationName(rel))));


    /*
     * Any insert which would have gone on the leaf block will now go to its
     * right sibling.  In other words, the key space moves right.
     */
    PredicateLockPageCombine(rel, leafblkno, leafrightsib);


    /* No ereport(ERROR) until changes are logged */
    START_CRIT_SECTION();