diff --git a/cpp/include/cudf/strings/contains.hpp b/cpp/include/cudf/strings/contains.hpp
index 9f408a40314..5b8b2f56bae 100644
--- a/cpp/include/cudf/strings/contains.hpp
+++ b/cpp/include/cudf/strings/contains.hpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2019, NVIDIA CORPORATION.
+ * Copyright (c) 2019-2022, NVIDIA CORPORATION.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -51,7 +51,7 @@ namespace strings {
  */
 std::unique_ptr<column> contains_re(
   strings_column_view const& strings,
-  std::string const& pattern,
+  std::string_view pattern,
   regex_flags const flags             = regex_flags::DEFAULT,
   rmm::mr::device_memory_resource* mr = rmm::mr::get_current_device_resource());
 
@@ -78,7 +78,7 @@ std::unique_ptr<column> contains_re(
  */
 std::unique_ptr<column> matches_re(
   strings_column_view const& strings,
-  std::string const& pattern,
+  std::string_view pattern,
   regex_flags const flags             = regex_flags::DEFAULT,
   rmm::mr::device_memory_resource* mr = rmm::mr::get_current_device_resource());
 
@@ -105,7 +105,7 @@ std::unique_ptr<column> matches_re(
  */
 std::unique_ptr<column> count_re(
   strings_column_view const& strings,
-  std::string const& pattern,
+  std::string_view pattern,
   regex_flags const flags             = regex_flags::DEFAULT,
   rmm::mr::device_memory_resource* mr = rmm::mr::get_current_device_resource());
 
diff --git a/cpp/include/cudf/strings/extract.hpp b/cpp/include/cudf/strings/extract.hpp
index 94e9f36d7d3..680d0f5b7bc 100644
--- a/cpp/include/cudf/strings/extract.hpp
+++ b/cpp/include/cudf/strings/extract.hpp
@@ -55,7 +55,7 @@ namespace strings {
  */
 std::unique_ptr<table> extract(
   strings_column_view const& strings,
-  std::string const& pattern,
+  std::string_view pattern,
   regex_flags const flags             = regex_flags::DEFAULT,
   rmm::mr::device_memory_resource* mr = rmm::mr::get_current_device_resource());
 
@@ -90,7 +90,7 @@ std::unique_ptr<table> extract(
  */
 std::unique_ptr<column> extract_all_record(
   strings_column_view const& strings,
-  std::string const& pattern,
+  std::string_view pattern,
   regex_flags const flags             = regex_flags::DEFAULT,
   rmm::mr::device_memory_resource* mr = rmm::mr::get_current_device_resource());
 
diff --git a/cpp/include/cudf/strings/findall.hpp b/cpp/include/cudf/strings/findall.hpp
index 25ebdc61673..25c6d523250 100644
--- a/cpp/include/cudf/strings/findall.hpp
+++ b/cpp/include/cudf/strings/findall.hpp
@@ -56,7 +56,7 @@ namespace strings {
  */
 std::unique_ptr<table> findall(
   strings_column_view const& input,
-  std::string const& pattern,
+  std::string_view pattern,
   regex_flags const flags             = regex_flags::DEFAULT,
   rmm::mr::device_memory_resource* mr = rmm::mr::get_current_device_resource());
 
@@ -90,7 +90,7 @@ std::unique_ptr<table> findall(
  */
 std::unique_ptr<column> findall_record(
   strings_column_view const& input,
-  std::string const& pattern,
+  std::string_view pattern,
   regex_flags const flags             = regex_flags::DEFAULT,
   rmm::mr::device_memory_resource* mr = rmm::mr::get_current_device_resource());
 
diff --git a/cpp/include/cudf/strings/replace_re.hpp b/cpp/include/cudf/strings/replace_re.hpp
index 0ab3953470d..36c287009d0 100644
--- a/cpp/include/cudf/strings/replace_re.hpp
+++ b/cpp/include/cudf/strings/replace_re.hpp
@@ -50,7 +50,7 @@ namespace strings {
  */
 std::unique_ptr<column> replace_re(
   strings_column_view const& strings,
-  std::string const& pattern,
+  std::string_view pattern,
   string_scalar const& replacement           = string_scalar(""),
   std::optional<size_type> max_replace_count = std::nullopt,
   regex_flags const flags                    = regex_flags::DEFAULT,
@@ -98,8 +98,8 @@ std::unique_ptr<column> replace_re(
  */
 std::unique_ptr<column> replace_with_backrefs(
   strings_column_view const& strings,
-  std::string const& pattern,
-  std::string const& replacement,
+  std::string_view pattern,
+  std::string_view replacement,
   regex_flags const flags             = regex_flags::DEFAULT,
   rmm::mr::device_memory_resource* mr = rmm::mr::get_current_device_resource());
 
diff --git a/cpp/include/cudf/strings/split/split_re.hpp b/cpp/include/cudf/strings/split/split_re.hpp
index 9f40956722d..57246bd91d2 100644
--- a/cpp/include/cudf/strings/split/split_re.hpp
+++ b/cpp/include/cudf/strings/split/split_re.hpp
@@ -71,7 +71,7 @@ namespace strings {
  */
 std::unique_ptr<table> split_re(
   strings_column_view const& input,
-  std::string const& pattern,
+  std::string_view pattern,
   size_type maxsplit                  = -1,
   rmm::mr::device_memory_resource* mr = rmm::mr::get_current_device_resource());
 
@@ -121,7 +121,7 @@ std::unique_ptr<table> split_re(
  */
 std::unique_ptr<table> rsplit_re(
   strings_column_view const& input,
-  std::string const& pattern,
+  std::string_view pattern,
   size_type maxsplit                  = -1,
   rmm::mr::device_memory_resource* mr = rmm::mr::get_current_device_resource());
 
@@ -173,7 +173,7 @@ std::unique_ptr<table> rsplit_re(
  */
 std::unique_ptr<column> split_record_re(
   strings_column_view const& input,
-  std::string const& pattern,
+  std::string_view pattern,
   size_type maxsplit                  = -1,
   rmm::mr::device_memory_resource* mr = rmm::mr::get_current_device_resource());
 
@@ -227,7 +227,7 @@ std::unique_ptr<column> split_record_re(
  */
 std::unique_ptr<column> rsplit_record_re(
   strings_column_view const& input,
-  std::string const& pattern,
+  std::string_view pattern,
   size_type maxsplit                  = -1,
   rmm::mr::device_memory_resource* mr = rmm::mr::get_current_device_resource());
 
diff --git a/cpp/src/strings/contains.cu b/cpp/src/strings/contains.cu
index 987cd076fd0..d75d914bb8e 100644
--- a/cpp/src/strings/contains.cu
+++ b/cpp/src/strings/contains.cu
@@ -56,7 +56,7 @@ struct contains_fn {
 };
 
 std::unique_ptr<column> contains_impl(strings_column_view const& input,
-                                      std::string const& pattern,
+                                      std::string_view pattern,
                                       regex_flags const flags,
                                       bool const beginning_only,
                                       rmm::cuda_stream_view stream,
@@ -85,7 +85,7 @@ std::unique_ptr<column> contains_impl(strings_column_view const& input,
 
 std::unique_ptr<column> contains_re(
   strings_column_view const& input,
-  std::string const& pattern,
+  std::string_view pattern,
   regex_flags const flags,
   rmm::cuda_stream_view stream,
   rmm::mr::device_memory_resource* mr = rmm::mr::get_current_device_resource())
@@ -95,7 +95,7 @@ std::unique_ptr<column> contains_re(
 
 std::unique_ptr<column> matches_re(
   strings_column_view const& input,
-  std::string const& pattern,
+  std::string_view pattern,
   regex_flags const flags,
   rmm::cuda_stream_view stream,
   rmm::mr::device_memory_resource* mr = rmm::mr::get_current_device_resource())
@@ -105,7 +105,7 @@ std::unique_ptr<column> matches_re(
 
 std::unique_ptr<column> count_re(
   strings_column_view const& input,
-  std::string const& pattern,
+  std::string_view pattern,
   regex_flags const flags,
   rmm::cuda_stream_view stream,
   rmm::mr::device_memory_resource* mr = rmm::mr::get_current_device_resource())
@@ -128,7 +128,7 @@ std::unique_ptr<column> count_re(
 // external APIs
 
 std::unique_ptr<column> contains_re(strings_column_view const& strings,
-                                    std::string const& pattern,
+                                    std::string_view pattern,
                                     regex_flags const flags,
                                     rmm::mr::device_memory_resource* mr)
 {
@@ -137,7 +137,7 @@ std::unique_ptr<column> contains_re(strings_column_view const& strings,
 }
 
 std::unique_ptr<column> matches_re(strings_column_view const& strings,
-                                   std::string const& pattern,
+                                   std::string_view pattern,
                                    regex_flags const flags,
                                    rmm::mr::device_memory_resource* mr)
 {
@@ -146,7 +146,7 @@ std::unique_ptr<column> matches_re(strings_column_view const& strings,
 }
 
 std::unique_ptr<column> count_re(strings_column_view const& strings,
-                                 std::string const& pattern,
+                                 std::string_view pattern,
                                  regex_flags const flags,
                                  rmm::mr::device_memory_resource* mr)
 {
diff --git a/cpp/src/strings/extract/extract.cu b/cpp/src/strings/extract/extract.cu
index 59b90952d97..018fb7ba2fb 100644
--- a/cpp/src/strings/extract/extract.cu
+++ b/cpp/src/strings/extract/extract.cu
@@ -85,7 +85,7 @@ struct extract_fn {
 
 //
 std::unique_ptr<table> extract(strings_column_view const& input,
-                               std::string const& pattern,
+                               std::string_view pattern,
                                regex_flags const flags,
                                rmm::cuda_stream_view stream,
                                rmm::mr::device_memory_resource* mr)
@@ -130,7 +130,7 @@ std::unique_ptr<table> extract(strings_column_view const& input,
 // external API
 
 std::unique_ptr<table> extract(strings_column_view const& strings,
-                               std::string const& pattern,
+                               std::string_view pattern,
                                regex_flags const flags,
                                rmm::mr::device_memory_resource* mr)
 {
diff --git a/cpp/src/strings/extract/extract_all.cu b/cpp/src/strings/extract/extract_all.cu
index 95b8a43a9d4..60c28027833 100644
--- a/cpp/src/strings/extract/extract_all.cu
+++ b/cpp/src/strings/extract/extract_all.cu
@@ -96,7 +96,7 @@ struct extract_fn {
  */
 std::unique_ptr<column> extract_all_record(
   strings_column_view const& input,
-  std::string const& pattern,
+  std::string_view pattern,
   regex_flags const flags,
   rmm::cuda_stream_view stream,
   rmm::mr::device_memory_resource* mr = rmm::mr::get_current_device_resource())
@@ -165,7 +165,7 @@ std::unique_ptr<column> extract_all_record(
 // external API
 
 std::unique_ptr<column> extract_all_record(strings_column_view const& strings,
-                                           std::string const& pattern,
+                                           std::string_view pattern,
                                            regex_flags const flags,
                                            rmm::mr::device_memory_resource* mr)
 {
diff --git a/cpp/src/strings/regex/regcomp.cpp b/cpp/src/strings/regex/regcomp.cpp
index f99acc3448a..dd4b4116994 100644
--- a/cpp/src/strings/regex/regcomp.cpp
+++ b/cpp/src/strings/regex/regcomp.cpp
@@ -21,7 +21,9 @@
 
 #include <algorithm>
 #include <array>
-#include <cstring>
+#include <numeric>
+#include <stack>
+#include <string>
 
 namespace cudf {
 namespace strings {
@@ -862,8 +864,7 @@ class regex_compiler {
       ;  // "unmatched left paren";
     /* points to first and only operand */
     m_prog.set_start_inst(andstack[andstack.size() - 1].id_first);
-    m_prog.optimize1();
-    m_prog.optimize2();
+    m_prog.finalize();
     m_prog.check_for_errors();
     m_prog.set_groups_count(cursubid);
   }
@@ -880,81 +881,78 @@ reprog reprog::create_from(std::string_view pattern, regex_flags const flags)
   return rtn;
 }
 
-//
-void reprog::optimize1()
+void reprog::finalize()
 {
-  // Treat non-capturing LBRAs/RBRAs as NOOP
-  for (int i = 0; i < static_cast<int>(_insts.size()); i++) {
-    if (_insts[i].type == LBRA || _insts[i].type == RBRA) {
-      if (_insts[i].u1.subid < 1) { _insts[i].type = NOP; }
+  collapse_nops();
+  build_start_ids();
+}
+
+void reprog::collapse_nops()
+{
+  // treat non-capturing LBRAs/RBRAs as NOP
+  std::transform(_insts.begin(), _insts.end(), _insts.begin(), [](auto inst) {
+    if ((inst.type == LBRA || inst.type == RBRA) && (inst.u1.subid < 1)) { inst.type = NOP; }
+    return inst;
+  });
+
+  // functor for finding the next valid op
+  auto find_next_op = [insts = _insts](int id) {
+    while (insts[id].type == NOP) {
+      id = insts[id].u2.next_id;
     }
-  }
+    return id;
+  };
 
-  // get rid of NOP chains
-  for (int i = 0; i < insts_count(); i++) {
-    if (_insts[i].type != NOP) {
-      {
-        int target_id = _insts[i].u2.next_id;
-        while (_insts[target_id].type == NOP)
-          target_id = _insts[target_id].u2.next_id;
-        _insts[i].u2.next_id = target_id;
-      }
-      if (_insts[i].type == OR) {
-        int target_id = _insts[i].u1.right_id;
-        while (_insts[target_id].type == NOP)
-          target_id = _insts[target_id].u2.next_id;
-        _insts[i].u1.right_id = target_id;
-      }
+  // create new routes around NOP chains
+  std::transform(_insts.begin(), _insts.end(), _insts.begin(), [find_next_op](auto inst) {
+    if (inst.type != NOP) {
+      inst.u2.next_id = find_next_op(inst.u2.next_id);
+      if (inst.type == OR) { inst.u1.right_id = find_next_op(inst.u1.right_id); }
     }
-  }
-  // skip NOPs from the beginning
-  {
-    int target_id = _startinst_id;
-    while (_insts[target_id].type == NOP)
-      target_id = _insts[target_id].u2.next_id;
-    _startinst_id = target_id;
-  }
-  // actually remove the no-ops
+    return inst;
+  });
+
+  // find starting op
+  _startinst_id = find_next_op(_startinst_id);
+
+  // build a map of op ids
+  // these are used to fix up the ids after the NOPs are removed
   std::vector<int> id_map(insts_count());
-  int j = 0;  // compact the ops (non no-ops)
-  for (int i = 0; i < insts_count(); i++) {
-    id_map[i] = j;
-    if (_insts[i].type != NOP) {
-      _insts[j] = _insts[i];
-      j++;
-    }
-  }
-  _insts.resize(j);
-  // fix up the ORs
-  for (int i = 0; i < insts_count(); i++) {
-    {
-      int target_id        = _insts[i].u2.next_id;
-      _insts[i].u2.next_id = id_map[target_id];
-    }
-    if (_insts[i].type == OR) {
-      int target_id         = _insts[i].u1.right_id;
-      _insts[i].u1.right_id = id_map[target_id];
-    }
-  }
-  // set the new start id
+  std::transform_exclusive_scan(
+    _insts.begin(), _insts.end(), id_map.begin(), 0, std::plus<int>{}, [](auto inst) {
+      return static_cast<int>(inst.type != NOP);
+    });
+
+  // remove the NOP instructions
+  auto end = std::remove_if(_insts.begin(), _insts.end(), [](auto i) { return i.type == NOP; });
+  _insts.resize(std::distance(_insts.begin(), end));
+
+  // fix up the ids on the remaining instructions using the id_map
+  std::transform(_insts.begin(), _insts.end(), _insts.begin(), [id_map](auto inst) {
+    inst.u2.next_id = id_map[inst.u2.next_id];
+    if (inst.type == OR) { inst.u1.right_id = id_map[inst.u1.right_id]; }
+    return inst;
+  });
+
+  // fix up the start instruction id too
   _startinst_id = id_map[_startinst_id];
 }
 
 // expand leading ORs to multiple startinst_ids
-void reprog::optimize2()
+void reprog::build_start_ids()
 {
   _startinst_ids.clear();
-  std::vector<int> stack;
-  stack.push_back(_startinst_id);
-  while (!stack.empty()) {
-    int id = stack.back();
-    stack.pop_back();
+  std::stack<int> ids;
+  ids.push(_startinst_id);
+  while (!ids.empty()) {
+    int id = ids.top();
+    ids.pop();
     const reinst& inst = _insts[id];
     if (inst.type == OR) {
       if (inst.u2.left_id != id)  // prevents infinite while-loop here
-        stack.push_back(inst.u2.left_id);
+        ids.push(inst.u2.left_id);
       if (inst.u1.right_id != id)  // prevents infinite while-loop here
-        stack.push_back(inst.u1.right_id);
+        ids.push(inst.u1.right_id);
     } else {
       _startinst_ids.push_back(id);
     }
diff --git a/cpp/src/strings/regex/regcomp.h b/cpp/src/strings/regex/regcomp.h
index 162a2090268..ed87660f106 100644
--- a/cpp/src/strings/regex/regcomp.h
+++ b/cpp/src/strings/regex/regcomp.h
@@ -124,8 +124,7 @@ class reprog {
   void set_start_inst(int32_t id);
   [[nodiscard]] int32_t get_start_inst() const;
 
-  void optimize1();
-  void optimize2();
+  void finalize();
   void check_for_errors();
 #ifndef NDEBUG
   void print(regex_flags const flags);
@@ -139,6 +138,8 @@ class reprog {
   int32_t _num_capturing_groups{};
 
   reprog() = default;
+  void collapse_nops();
+  void build_start_ids();
   void check_for_errors(int32_t id, int32_t next_id);
 };
 
diff --git a/cpp/src/strings/regex/regex.cuh b/cpp/src/strings/regex/regex.cuh
index 5ccc70222d5..2ee195a2c5e 100644
--- a/cpp/src/strings/regex/regex.cuh
+++ b/cpp/src/strings/regex/regex.cuh
@@ -88,7 +88,7 @@ class reprog_device {
    * @return The program device object.
    */
   static std::unique_ptr<reprog_device, std::function<void(reprog_device*)>> create(
-    std::string const& pattern, rmm::cuda_stream_view stream);
+    std::string_view pattern, rmm::cuda_stream_view stream);
 
   /**
    * @brief Create the device program instance from a regex pattern.
@@ -99,7 +99,7 @@ class reprog_device {
    * @return The program device object.
    */
   static std::unique_ptr<reprog_device, std::function<void(reprog_device*)>> create(
-    std::string const& pattern, regex_flags const re_flags, rmm::cuda_stream_view stream);
+    std::string_view pattern, regex_flags const re_flags, rmm::cuda_stream_view stream);
 
   /**
    * @brief Called automatically by the unique_ptr returned from create().
diff --git a/cpp/src/strings/regex/regexec.cu b/cpp/src/strings/regex/regexec.cu
index 4b58d9d8a88..16f5b6fa03d 100644
--- a/cpp/src/strings/regex/regexec.cu
+++ b/cpp/src/strings/regex/regexec.cu
@@ -43,14 +43,14 @@ reprog_device::reprog_device(reprog& prog)
 }
 
 std::unique_ptr<reprog_device, std::function<void(reprog_device*)>> reprog_device::create(
-  std::string const& pattern, rmm::cuda_stream_view stream)
+  std::string_view pattern, rmm::cuda_stream_view stream)
 {
   return reprog_device::create(pattern, regex_flags::MULTILINE, stream);
 }
 
 // Create instance of the reprog that can be passed into a device kernel
 std::unique_ptr<reprog_device, std::function<void(reprog_device*)>> reprog_device::create(
-  std::string const& pattern, regex_flags const flags, rmm::cuda_stream_view stream)
+  std::string_view pattern, regex_flags const flags, rmm::cuda_stream_view stream)
 {
   // compile pattern into host object
   reprog h_prog = reprog::create_from(pattern, flags);
diff --git a/cpp/src/strings/replace/backref_re.cu b/cpp/src/strings/replace/backref_re.cu
index 107adf07263..55498e760ff 100644
--- a/cpp/src/strings/replace/backref_re.cu
+++ b/cpp/src/strings/replace/backref_re.cu
@@ -46,13 +46,14 @@ namespace {
  *
  * Reference: https://www.regular-expressions.info/refreplacebackref.html
  */
-std::string get_backref_pattern(std::string const& repl)
+std::string get_backref_pattern(std::string_view repl)
 {
   std::string const backslash_pattern = "\\\\(\\d+)";
   std::string const bracket_pattern   = "\\$\\{(\\d+)\\}";
+  std::string const r{repl};
   std::smatch m;
-  return std::regex_search(repl, m, std::regex(backslash_pattern)) ? backslash_pattern
-                                                                   : bracket_pattern;
+  return std::regex_search(r, m, std::regex(backslash_pattern)) ? backslash_pattern
+                                                                : bracket_pattern;
 }
 /**
  * @brief Parse the back-ref index and position values from a given replace format.
@@ -66,11 +67,11 @@ std::string get_backref_pattern(std::string const& repl)
  * For example, for input string 'hello \2 and \1' the returned `backref_type` vector
  * contains `[(2,6),(1,11)]` and the returned string is 'hello  and '.
  */
-std::pair<std::string, std::vector<backref_type>> parse_backrefs(std::string const& repl,
+std::pair<std::string, std::vector<backref_type>> parse_backrefs(std::string_view repl,
                                                                  int const group_count)
 {
   std::vector<backref_type> backrefs;
-  std::string str = repl;  // make a modifiable copy
+  std::string str{repl};  // make a modifiable copy
   std::smatch m;
   std::regex ex(get_backref_pattern(repl));
   std::string rtn;
@@ -100,8 +101,8 @@ std::pair<std::string, std::vector<backref_type>> parse_backrefs(std::string con
 
 //
 std::unique_ptr<column> replace_with_backrefs(strings_column_view const& input,
-                                              std::string const& pattern,
-                                              std::string const& replacement,
+                                              std::string_view pattern,
+                                              std::string_view replacement,
                                               regex_flags const flags,
                                               rmm::cuda_stream_view stream,
                                               rmm::mr::device_memory_resource* mr)
@@ -144,8 +145,8 @@ std::unique_ptr<column> replace_with_backrefs(strings_column_view const& input,
 // external API
 
 std::unique_ptr<column> replace_with_backrefs(strings_column_view const& strings,
-                                              std::string const& pattern,
-                                              std::string const& replacement,
+                                              std::string_view pattern,
+                                              std::string_view replacement,
                                               regex_flags const flags,
                                               rmm::mr::device_memory_resource* mr)
 {
diff --git a/cpp/src/strings/replace/replace_re.cu b/cpp/src/strings/replace/replace_re.cu
index 159f83453bd..1ed29587ac7 100644
--- a/cpp/src/strings/replace/replace_re.cu
+++ b/cpp/src/strings/replace/replace_re.cu
@@ -101,7 +101,7 @@ struct replace_regex_fn {
 //
 std::unique_ptr<column> replace_re(
   strings_column_view const& input,
-  std::string const& pattern,
+  std::string_view pattern,
   string_scalar const& replacement,
   std::optional<size_type> max_replace_count,
   regex_flags const flags,
@@ -135,7 +135,7 @@ std::unique_ptr<column> replace_re(
 // external API
 
 std::unique_ptr<column> replace_re(strings_column_view const& strings,
-                                   std::string const& pattern,
+                                   std::string_view pattern,
                                    string_scalar const& replacement,
                                    std::optional<size_type> max_replace_count,
                                    regex_flags const flags,
diff --git a/cpp/src/strings/search/findall.cu b/cpp/src/strings/search/findall.cu
index 64e46d07e25..c92e1e7bbd9 100644
--- a/cpp/src/strings/search/findall.cu
+++ b/cpp/src/strings/search/findall.cu
@@ -86,7 +86,7 @@ struct findall_fn {
 }  // namespace
 
 std::unique_ptr<table> findall(strings_column_view const& input,
-                               std::string const& pattern,
+                               std::string_view pattern,
                                regex_flags const flags,
                                rmm::cuda_stream_view stream,
                                rmm::mr::device_memory_resource* mr)
@@ -147,7 +147,7 @@ std::unique_ptr<table> findall(strings_column_view const& input,
 // external API
 
 std::unique_ptr<table> findall(strings_column_view const& input,
-                               std::string const& pattern,
+                               std::string_view pattern,
                                regex_flags const flags,
                                rmm::mr::device_memory_resource* mr)
 {
diff --git a/cpp/src/strings/search/findall_record.cu b/cpp/src/strings/search/findall_record.cu
index 2f4b9ce5b24..e4cf4dad618 100644
--- a/cpp/src/strings/search/findall_record.cu
+++ b/cpp/src/strings/search/findall_record.cu
@@ -93,7 +93,7 @@ std::unique_ptr<column> findall_util(column_device_view const& d_strings,
 //
 std::unique_ptr<column> findall_record(
   strings_column_view const& input,
-  std::string const& pattern,
+  std::string_view pattern,
   regex_flags const flags,
   rmm::cuda_stream_view stream,
   rmm::mr::device_memory_resource* mr = rmm::mr::get_current_device_resource())
@@ -133,7 +133,7 @@ std::unique_ptr<column> findall_record(
 // external API
 
 std::unique_ptr<column> findall_record(strings_column_view const& input,
-                                       std::string const& pattern,
+                                       std::string_view pattern,
                                        regex_flags const flags,
                                        rmm::mr::device_memory_resource* mr)
 {
diff --git a/cpp/src/strings/split/split_re.cu b/cpp/src/strings/split/split_re.cu
index 16edd0606e9..750f5fbe942 100644
--- a/cpp/src/strings/split/split_re.cu
+++ b/cpp/src/strings/split/split_re.cu
@@ -184,7 +184,7 @@ struct tokens_transform_fn {
 };
 
 std::unique_ptr<table> split_re(strings_column_view const& input,
-                                std::string const& pattern,
+                                std::string_view pattern,
                                 split_direction direction,
                                 size_type maxsplit,
                                 rmm::cuda_stream_view stream,
@@ -252,7 +252,7 @@ std::unique_ptr<table> split_re(strings_column_view const& input,
 }
 
 std::unique_ptr<column> split_record_re(strings_column_view const& input,
-                                        std::string const& pattern,
+                                        std::string_view pattern,
                                         split_direction direction,
                                         size_type maxsplit,
                                         rmm::cuda_stream_view stream,
@@ -289,7 +289,7 @@ std::unique_ptr<column> split_record_re(strings_column_view const& input,
 }  // namespace
 
 std::unique_ptr<table> split_re(strings_column_view const& input,
-                                std::string const& pattern,
+                                std::string_view pattern,
                                 size_type maxsplit,
                                 rmm::cuda_stream_view stream,
                                 rmm::mr::device_memory_resource* mr)
@@ -298,7 +298,7 @@ std::unique_ptr<table> split_re(strings_column_view const& input,
 }
 
 std::unique_ptr<column> split_record_re(strings_column_view const& input,
-                                        std::string const& pattern,
+                                        std::string_view pattern,
                                         size_type maxsplit,
                                         rmm::cuda_stream_view stream,
                                         rmm::mr::device_memory_resource* mr)
@@ -307,7 +307,7 @@ std::unique_ptr<column> split_record_re(strings_column_view const& input,
 }
 
 std::unique_ptr<table> rsplit_re(strings_column_view const& input,
-                                 std::string const& pattern,
+                                 std::string_view pattern,
                                  size_type maxsplit,
                                  rmm::cuda_stream_view stream,
                                  rmm::mr::device_memory_resource* mr)
@@ -316,7 +316,7 @@ std::unique_ptr<table> rsplit_re(strings_column_view const& input,
 }
 
 std::unique_ptr<column> rsplit_record_re(strings_column_view const& input,
-                                         std::string const& pattern,
+                                         std::string_view pattern,
                                          size_type maxsplit,
                                          rmm::cuda_stream_view stream,
                                          rmm::mr::device_memory_resource* mr)
@@ -329,7 +329,7 @@ std::unique_ptr<column> rsplit_record_re(strings_column_view const& input,
 // external APIs
 
 std::unique_ptr<table> split_re(strings_column_view const& input,
-                                std::string const& pattern,
+                                std::string_view pattern,
                                 size_type maxsplit,
                                 rmm::mr::device_memory_resource* mr)
 {
@@ -338,7 +338,7 @@ std::unique_ptr<table> split_re(strings_column_view const& input,
 }
 
 std::unique_ptr<column> split_record_re(strings_column_view const& input,
-                                        std::string const& pattern,
+                                        std::string_view pattern,
                                         size_type maxsplit,
                                         rmm::mr::device_memory_resource* mr)
 {
@@ -347,7 +347,7 @@ std::unique_ptr<column> split_record_re(strings_column_view const& input,
 }
 
 std::unique_ptr<table> rsplit_re(strings_column_view const& input,
-                                 std::string const& pattern,
+                                 std::string_view pattern,
                                  size_type maxsplit,
                                  rmm::mr::device_memory_resource* mr)
 {
@@ -356,7 +356,7 @@ std::unique_ptr<table> rsplit_re(strings_column_view const& input,
 }
 
 std::unique_ptr<column> rsplit_record_re(strings_column_view const& input,
-                                         std::string const& pattern,
+                                         std::string_view pattern,
                                          size_type maxsplit,
                                          rmm::mr::device_memory_resource* mr)
 {
diff --git a/java/src/main/java/ai/rapids/cudf/Cuda.java b/java/src/main/java/ai/rapids/cudf/Cuda.java
index 21843527fc2..56a754279fc 100755
--- a/java/src/main/java/ai/rapids/cudf/Cuda.java
+++ b/java/src/main/java/ai/rapids/cudf/Cuda.java
@@ -596,4 +596,10 @@ public static void multiBufferCopyAsync(long [] destAddrs,
    * no effect.
    */
   public static native void profilerStop();
+
+  /**
+   * Synchronizes the whole device using cudaDeviceSynchronize.
+   * @note this is very expensive and should almost never be used
+   */
+  public static native void deviceSynchronize();
 }
diff --git a/java/src/main/native/src/CudaJni.cpp b/java/src/main/native/src/CudaJni.cpp
index 926521c55f9..ce1ad1b1671 100644
--- a/java/src/main/native/src/CudaJni.cpp
+++ b/java/src/main/native/src/CudaJni.cpp
@@ -390,4 +390,12 @@ JNIEXPORT void JNICALL Java_ai_rapids_cudf_Cuda_profilerStop(JNIEnv *env, jclass
   CATCH_STD(env, );
 }
 
+JNIEXPORT void JNICALL Java_ai_rapids_cudf_Cuda_deviceSynchronize(JNIEnv *env, jclass clazz) {
+  try {
+    cudf::jni::auto_set_device(env);
+    CUDF_CUDA_TRY(cudaDeviceSynchronize());
+  }
+  CATCH_STD(env, );
+}
+
 } // extern "C"
diff --git a/python/cudf/cudf/core/resample.py b/python/cudf/cudf/core/resample.py
index 2bed71ea751..57630e7d4a9 100644
--- a/python/cudf/cudf/core/resample.py
+++ b/python/cudf/cudf/core/resample.py
@@ -1,4 +1,4 @@
-# SPDX-FileCopyrightText: Copyright (c) 2021 NVIDIA CORPORATION &
+# SPDX-FileCopyrightText: Copyright (c) 2021-2022, NVIDIA CORPORATION &
 # AFFILIATES. All rights reserved.  SPDX-License-Identifier:
 # Apache-2.0
 #
diff --git a/python/dask_cudf/dask_cudf/groupby.py b/python/dask_cudf/dask_cudf/groupby.py
index a64aabe1a6b..22705c2b83b 100644
--- a/python/dask_cudf/dask_cudf/groupby.py
+++ b/python/dask_cudf/dask_cudf/groupby.py
@@ -245,6 +245,7 @@ def last(self, split_every=None, split_out=1):
     def aggregate(self, arg, split_every=None, split_out=1):
         if arg == "size":
             return self.size()
+
         arg = _redirect_aggs(arg)
 
         if _groupby_supported(self) and _aggs_supported(arg, SUPPORTED_AGGS):
@@ -431,6 +432,7 @@ def last(self, split_every=None, split_out=1):
     def aggregate(self, arg, split_every=None, split_out=1):
         if arg == "size":
             return self.size()
+
         arg = _redirect_aggs(arg)
 
         if not isinstance(arg, dict):
@@ -503,7 +505,7 @@ def groupby_agg(
     if isinstance(gb_cols, str):
         gb_cols = [gb_cols]
     columns = [c for c in ddf.columns if c not in gb_cols]
-    if isinstance(aggs, list):
+    if not isinstance(aggs, dict):
         aggs = {col: aggs for col in columns}
 
     # Assert if our output will have a MultiIndex; this will be the case if
@@ -665,6 +667,8 @@ def _aggs_supported(arg, supported: set):
             _global_set = set(arg)
 
         return bool(_global_set.issubset(supported))
+    elif isinstance(arg, str):
+        return arg in supported
     return False
 
 
diff --git a/python/dask_cudf/dask_cudf/tests/test_groupby.py b/python/dask_cudf/dask_cudf/tests/test_groupby.py
index 5aa9cffb789..2b7f2bdae36 100644
--- a/python/dask_cudf/dask_cudf/tests/test_groupby.py
+++ b/python/dask_cudf/dask_cudf/tests/test_groupby.py
@@ -58,7 +58,10 @@ def test_groupby_basic(series, aggregation):
     "func",
     [
         lambda df: df.groupby("x").agg({"y": "max"}),
+        lambda df: df.groupby("x").agg(["sum", "max"]),
         lambda df: df.groupby("x").y.agg(["sum", "max"]),
+        lambda df: df.groupby("x").agg("sum"),
+        lambda df: df.groupby("x").y.agg("sum"),
     ],
 )
 def test_groupby_agg(func):
@@ -663,11 +666,20 @@ def test_groupby_agg_redirect(aggregations):
 
 
 @pytest.mark.parametrize(
-    "arg",
-    [["not_supported"], {"a": "not_supported"}, {"a": ["not_supported"]}],
+    "arg,supported",
+    [
+        ("sum", True),
+        (["sum"], True),
+        ({"a": "sum"}, True),
+        ({"a": ["sum"]}, True),
+        ("not_supported", False),
+        (["not_supported"], False),
+        ({"a": "not_supported"}, False),
+        ({"a": ["not_supported"]}, False),
+    ],
 )
-def test_is_supported(arg):
-    assert _aggs_supported(arg, {"supported"}) is False
+def test_is_supported(arg, supported):
+    assert _aggs_supported(arg, SUPPORTED_AGGS) is supported
 
 
 def test_groupby_unique_lists():