From e2637ab6a78992457e4bc98efe2c3614a14b7651 Mon Sep 17 00:00:00 2001
From: Alex Duan <417921451@qq.com>
Date: Tue, 18 Oct 2022 17:22:41 +0800
Subject: [PATCH] fix(query): improve performance for first function x10
 quickly

---
 source/libs/function/src/builtins.c     |  2 ++
 source/libs/function/src/builtinsimpl.c | 16 ++++++++++++++++
 2 files changed, 18 insertions(+)

diff --git a/source/libs/function/src/builtins.c b/source/libs/function/src/builtins.c
index 2308aaf214..49facfdd14 100644
--- a/source/libs/function/src/builtins.c
+++ b/source/libs/function/src/builtins.c
@@ -2431,6 +2431,7 @@ const SBuiltinFuncDefinition funcMgtBuiltins[] = {
     .type = FUNCTION_TYPE_FIRST,
     .classification = FUNC_MGT_AGG_FUNC | FUNC_MGT_SELECT_FUNC | FUNC_MGT_MULTI_RES_FUNC | FUNC_MGT_IMPLICIT_TS_FUNC,
     .translateFunc = translateFirstLast,
+    .dynDataRequiredFunc = firstDynDataReq,
     .getEnvFunc   = getFirstLastFuncEnv,
     .initFunc     = functionSetup,
     .processFunc  = firstFunction,
@@ -2445,6 +2446,7 @@ const SBuiltinFuncDefinition funcMgtBuiltins[] = {
     .type = FUNCTION_TYPE_FIRST_PARTIAL,
     .classification = FUNC_MGT_AGG_FUNC | FUNC_MGT_SELECT_FUNC | FUNC_MGT_MULTI_RES_FUNC | FUNC_MGT_IMPLICIT_TS_FUNC,
     .translateFunc = translateFirstLastPartial,
+    .dynDataRequiredFunc = firstDynDataReq,
     .getEnvFunc   = getFirstLastFuncEnv,
     .initFunc     = functionSetup,
     .processFunc  = firstFunction,
diff --git a/source/libs/function/src/builtinsimpl.c b/source/libs/function/src/builtinsimpl.c
index 7077a9b780..a756c27bb5 100644
--- a/source/libs/function/src/builtinsimpl.c
+++ b/source/libs/function/src/builtinsimpl.c
@@ -2717,6 +2717,22 @@ int32_t apercentileCombine(SqlFunctionCtx* pDestCtx, SqlFunctionCtx* pSourceCtx)
   return TSDB_CODE_SUCCESS;
 }
 
+EFuncDataRequired firstDynDataReq(void* pRes, STimeWindow* pTimeWindow) {
+  SResultRowEntryInfo* pEntry = (SResultRowEntryInfo*)pRes;
+
+  // not initialized yet, data is required
+  if (pEntry == NULL) {
+    return FUNC_DATA_REQUIRED_DATA_LOAD;
+  }
+
+  SFirstLastRes* pResult = GET_ROWCELL_INTERBUF(pEntry);
+  if (pResult->hasResult && pResult->ts <= pTimeWindow->skey) {
+    return FUNC_DATA_REQUIRED_NOT_LOAD;
+  } else {
+    return FUNC_DATA_REQUIRED_DATA_LOAD;
+  }
+}
+
 EFuncDataRequired lastDynDataReq(void* pRes, STimeWindow* pTimeWindow) {
   SResultRowEntryInfo* pEntry = (SResultRowEntryInfo*)pRes;
 
-- 
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